[Federal Register: September 24, 2002 (Volume 67, Number 185)]
[Proposed Rules]               
[Page 59933-59982]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr24se02-26]                         
 
[[pp. 59933-59982]] Endangered and Threatened Wildlife and Plants; Critical Habitat 
Designation for Four Vernal Pool Crustaceans and Eleven Vernal Pool 
Plants in California and Southern Oregon

[[Continued from page 59932]]

[[Page 59933]]

2000). This unit contains some of the few areas where vernal pool 
tadpole shrimp are found in Northern Volcanic Mudflow vernal pools, 
including vernal pools found on the Tuscan and Lovejoy Basalt geologic 
formations. Vernal pool tadpole shrimp also occur within Northern 
Hardpan vernal pools in this unit, including pools formed on the 
Riverbank and Modesto geologic formations. King (1996) found that 
vernal pool tadpole shrimp at this site were genetically distinct from 
vernal pool tadpole shrimp at other locations.
    The majority of the lands included within this unit are privately 
owned. Ownership and protected lands within the unit includes BLM (48 
ha (119 ac)), USFS (78 ha (194 ac)), WRP easements (14 ha (35 ac)), and 
CDFG administered lands (69 ha (173 ac)). The CDFG has some vernal pool 
areas protected at the Oroville Wildlife Area, and some vernal pool 
habitats are protected within the City of Chico. However, the amount of 
vernal pool habitat currently protected within the unit is very small. 
Vernal pools in this unit are highly threatened due to their location 
on the lower elevation slopes adjacent to agricultural and urban 
development. Urban expansion, particularly in the vicinity of Chico, is 
the greatest threat to existing vernal pool habitats throughout this 
unit.
    The boundaries of this unit were delineated to include the 
interconnected pools, swales, and associated uplands mapped by Holland 
(1998) that contribute to the filling and drying of the vernal pools 
where vernal pool tadpole shrimp occur, and maintain suitable periods 
of pool inundation, water quality, and soil moisture for vernal pool 
tadpole shrimp to hatch, feed, and reproduce.
    This unit occupies the northeastern portion of the Sacramento 
Valley from near Chico south to the Yuba River in Yuba County. This 
area represents one of only two vernal pool tadpole shrimp units within 
the Northeastern Sacramento Valley vernal pool region identified by 
CDFG (Keeler Wolf et al. 1998). The unit extends southeast of the 
Sacramento River paralleling the low elevation foothill region of the 
Sierra Nevada. This unit incorporates portions of Unit 2 for Butte 
County meadow foam and fully incorporates Unit 9 for vernal pool fairy 
shrimp, Units 3 for Greene's tuctoria, Unit 2 for hairy Orcutt grass, 
Unit 2 for Hoover's spurge, and Unit 4 for Butte County meadowfoam. 
Other vernal pool species occurring within this unit include Bogg's 
Lake hedge-hyssop, Red Bluff dwarf rush, Douglas' pogogyne, western 
spadefoot toad, legenere, California linderiella, California tiger 
salamander, Ahart's paronychia, Henderson's bent grass, Sanford's 
arrowhead, and dwarf downingia.

Unit 5, Sacramento National Wildlife Refuge Unit, Glenn and Colusa 
Counties (5,718 ha (14,129 ac))

    This unit is proposed as critical for vernal pool tadpole shrimp 
because it contains the primary constituent elements necessary for the 
conservation of the species, and supports occurrences of the species 
(Holland 1998, Silveira 2000, CNDDB 2001). Vernal pool tadpole shrimp 
within this unit live within Northern Claypan and Northern Hardpan 
vernal pools, as defined by Sawyer and Keeler-Wolf (1995). The edaphic 
features that support the formation of these vernal pools include the 
Modesto geologic formation and Willows and Riz soils series. These 
vernal pools occur on alkaline soils and typically form alkali playas 
which are larger and contain a more diverse species composition than 
the hardpan pools further south (Keeler-Wolf et al. 1998). They may 
resemble small alkali playas, and display white salt deposits following 
pool drying.
    This unit is primarily located on the Sacramento National Wildlife 
Refuge (5,126 ha (12,816 ac)); however, additional private lands were 
included within this unit. The refuge supports over 355 native plant 
taxa, including a number of rare alkaline species. The Sacramento 
National Wildlife Refuge contains the only remnants of the widespread 
Colusa Plains vegetation that once covered the entire Colusa Basin 
(Silveira 2000). Vernal pool habitats on the refuge are specifically 
managed for the conservation of listed species, and to promote habitat 
for migratory birds and waterfowl. These avian species likely aid in 
the dispersal of vernal pool tadpole shrimp and other vernal pool 
crustacean cysts. Vernal pool habitats within the area have become 
greatly fragmented and isolated from other habitats in the region due 
to agricultural and urban land conversion.
    This unit occurs east of Interstate 5 to the Colusa Trough from Riz 
Road on the north and Delevan Road on the south. This unit coincides 
with Unit 1 for Colusa grass, Unit 6 for Greene's tuctoria, Unit 3 for 
hairy Orcutt grass, Unit 3 for Hoover's spurge, and Unit 2 for 
Conservancy fairy shrimp. Other important vernal pool and associated 
upland species found in the unit include pappose spikeweed, Fremont's 
goldfields, alkali goldfields, Scribe's popcorn flower, Hoover's 
downingia, folded downingia, Heckard's peppergrass, heartscale, 
brittlescale, San Joaquin spearscale, Ferris' milk-vetch, spike-
primrose, sessile mousetail, and palmate-bracted bird's beak.

Unit 6, Dolan Unit, Glenn and Colusa Counties (526 ha (1,299 ac))

    This unit is proposed as critical for vernal pool tadpole shrimp 
because it contains the primary constituent elements necessary for the 
conservation of the species and supports occurrences of the species 
(Holland 1998, Silveira 2000, CNDDB 2001). Vernal pool tadpole shrimp 
within this unit live within Northern Claypan vernal pools, as defined 
by Sawyer and Keeler-Wolf (1995). These vernal pools occur on alkaline 
soils and typically form alkali playas which are larger and contain a 
more diverse species composition than the hardpan pools further south 
(Keeler-Wolf et al. 1998). They may display white salt deposits 
following pool drying.
    This unit is primarily located on the Dolan Ranch Conservation 
bank. This area supports a number of rare alkaline species, and 
contains remnants of the widespread Colusa Plains vegetation that once 
covered the entire Colusa Basin (Silveira 2000). Vernal pool habitats 
on Dolan Ranch are specifically managed for the conservation of listed 
species. Vernal pool habitats within the area have become greatly 
fragmented and isolated from other habitats in the region due to urban 
and agricultural land conversions. This unit occurs east of Interstate 
5 and the Sacramento River, south of the City of Colusa, and west of 
the Colusa National Wildlife Refuge. All the lands within this unit are 
privately owned.

Unit 7, Beale Unit, Yuba and Placer Counties (2,853 ha (7,049 ac))

    The Beale Unit is proposed as essential because it contains vernal 
pool tadpole shrimp occurrences within large vernal pool complexes that 
maintain the primary constituent elements essential for the 
conservation of the species (Holland 1998, CNDDB 2001, Jones and Stokes 
2002). Vernal pool tadpole shrimp within the Beale Unit live within 
large, relatively undisturbed vernal pool grassland habitats and a 
diversity of vernal pool habitat types. Beale Air Force Base contains 
8,000 ha (19,800 ac) of vernal pool grasslands occurring on four major 
geologic formations: the Modesto Formation; the Riverbank Formation; 
the Laguna Formation; and the Mehrten Formation. Different geologic 
formations provide a diversity of habitats for vernal pool tadpole 
shrimp primarily through their effects on pool size and depth 
(Platenkamp 1998, Helm 1998). King

[[Page 59934]]

(1996) found that vernal pool tadpole shrimp within this unit were 
genetically different than occurrences in other portions of the species 
range, particularly those on the floor of the Central Valley. This unit 
is also designated to ensure that special management actions are taken 
to protect vernal pool habitats within the unit, including vernal pools 
created and restored throughout the unit which require long-term 
monitoring and management to ensure they continue to function as viable 
vernal pools. This unit is also important to maintain an opportunity 
for long distance dispersal of vernal pool tadpole shrimp cysts the 
nearest unit to the north is over 45 km (28 mi), and the nearest unit 
to the south is over 65 km (40 mi) away.
    This unit contains DOD land (2,006 ha (5,016 ac) at Beale Air Force 
Base and 5 ha (13 ac) of BLM land. Other lands within this unit are 
located on private property. Remaining vernal pool habitats in this 
unit are threatened by agricultural conversion and by urban expansion. 
Vernal pool habitats in this area are also threatened by the expansion 
of Highway 70 and other transportation projects planned in the region.
    The Beale Unit is located in southwestern Yuba County, south of the 
Yuba River and Yuba Goldfields, east of State Route 70, and north of 
the Bear River. The northwestern boundary of the unit borders the City 
of Marysville. Other rare vernal pool species found in this unit 
include vernal pool fairy shrimp, California linderiella, legenere, and 
dwarf downingia.

Unit 8, Mather Unit, Sacramento County (14,866 ha (36,733 ac))

    This unit is proposed as critical habitat for vernal pool tadpole 
shrimp because it contains 15 percent of all known occurrences of the 
species (CNDDB 2001) and vernal pools, swales, and other ephemeral 
wetlands and depressions mapped by Sacramento County (1999) and Holland 
(1998) of appropriate sizes and depths for vernal pool tadpole to 
complete their life cycle. These areas have been identified by the 
Sacramento Valley Open Space Conservancy, the CNPS, and TNC as 
excellent examples of vernal pool grasslands, supporting a rich and 
diverse community of vernal pool endemic plants and animals including 
vernal pool tadpole shrimp.
    This unit supports vernal pool tadpole shrimp occurrences within a 
diversity of vernal pool habitats, including young or low terrace 
vernal pools on the Riverbank Formation, old or high terrace vernal 
pools on the Laguna and Arroyo Seco geologic formations, and Northern 
Volcanic Mudflow vernal pools on the Mehrten and Valley Springs 
geologic formations. This unit is one of the few remaining areas where 
vernal pool tadpole shrimp occur on low terrace landforms on the 
eastern side of the Central Valley, and is important to maintain a 
diversity of habitats for the species. The boundaries of this unit were 
delineated to include the interconnected pools, swales, and associated 
uplands mapped by Holland (1998) that contribute to the filling and 
drying of the vernal pools where vernal pool tadpole shrimp occur, and 
maintain suitable periods of pool inundation, water quality, and soil 
moisture for vernal pool tadpole shrimp to hatch, mature, and produce 
cysts.
    This unit includes several conservation areas established by 
private entities, including the Sunrise Douglas Conservation Bank, the 
Arroyo Seco Conservation Bank, the Churchill Downs mitigation area, and 
Teichert mitigation areas. These areas were established specifically to 
contribute to the conservation of vernal pool tadpole shrimp, and 
represent compensation measures for the loss of thousands of acres of 
vernal pool tadpole shrimp habitat within Sacramento County. The 
continued functioning of these areas is essential to the conservation 
of vernal pool tadpole shrimp and other vernal pool species. This unit 
contains areas on private, county, and Federal land, including lands 
leased or owned by Sacramento County at Mather Regional Park, the 
former Mather Air Force Base, and at the county landfill. Approximately 
6 ha (16 ac) within this unit are BLM lands. Vernal pool habitats in 
this unit are threatened by urbanization from the expanding cities of 
Sacramento and Elk Grove. Conversion to intensive agriculture, 
particularly vineyards, is also a significant threat to vernal pool 
tadpole shrimp in this unit.
    This unit includes areas to the east and south of the cities of 
Sacramento and Elk Grove in Sacramento County. The Cosumnes River forms 
part of the southwestern boundary of the unit and State Highway 16 lies 
just south of the southeastern boundary of the unit. The northern 
boundary is south of State Highway 50 and the American River. The 
eastern boundary of this unit lies just west of Latrobe Road. The unit 
is bisected by the Folsom South Canal. This unit also represents Unit 
13 for vernal pool fairy shrimp, and contains Unit 6 for slender Orcutt 
grass and Unit 2 for the Sacramento Orcutt grass. In addition to vernal 
pool tadpole shrimp, this unit contains occurrences of many other rare 
endemic vernal pool species including midvalley fairy shrimp, legenere, 
Bogg's Lake hedge-hyssop, Ahart's dwarf rush, western spadefoot toad, 
and California linderiella.

Unit 9, Cosumnes Unit, Sacramento, Amador, and San Joaquin Counties 
(29,063 ha (71,813 ac))

    This unit is proposed as critical habitat for vernal pool tadpole 
shrimp because it contains the primary constituent elements necessary 
for the species survival, including over 30 percent of the remaining 
vernal pool habitats in the southern Sacramento Valley area (Holland 
1998, Sacramento County 1999). These habitats provide the necessary 
timing, length, and frequency of inundation necessary for the survival 
of vernal pool tadpole shrimp, and this unit supports numerous 
occurrences of the species (CNDDB 2001). Vernal pool tadpole shrimp 
within this unit occur on a diversity of pool types, including Northern 
Volcanic Mudflow vernal pools on the Mehrten and Valley Springs 
geologic formation overlain by Pardee and Pentz soils, vernal pools 
occurring on low terrace landforms associated with San Joaquin soils, 
and high terrace landforms associated with Redding and Corning soils 
(USDA 2001). King (1996) found that vernal pool tadpole shrimp within 
this unit were genetically most similar to occurrences in Stanislaus 
County and nearby in Sacramento County. However, vernal pool tadpole 
shrimp within this unit were generally different from occurrences at 
other sites sampled throughout the species range, and were very 
different from vernal pool tadpole shrimp sampled at sites found 
further to the west on the floor of the Central Valley, for example at 
Jepson Prairie or Kesterson National Wildlife Refuge (King 1996).
    The boundaries of this unit were delineated to include the 
interconnected pools, swales, and associated uplands mapped by Holland 
(1998) that contribute to the filling and drying of the vernal pools 
where vernal pool tadpole shrimp occur, and maintain suitable periods 
of pool inundation, water quality, and soil moisture for vernal pool 
tadpole shrimp to complete their life cycles.
    This unit contains state and federally owned land, as well as 
private properties. Portions of the Cosumnes River Preserve occur 
within this unit. The Cosumnes River Preserve is jointly owned and 
managed by a variety of state, local, and Federal agencies including 
the BLM , CDFG, Ducks Unlimited, Inc., California Department

[[Page 59935]]

of Water Resources, Sacramento Co. Dept. of Regional Parks, Open Space, 
and Recreation, TNC, and the Wildlife Conservation Board. The Cosumnes 
River Preserve encompasses and protects thousands of acres of wetlands 
and adjacent uplands, oak woodlands, and riparian forests along the 
Cosumnes River, the only undammed river on the west slope of the 
Sierra. The Cosumnes floodplain is a haven for tens of thousands of 
migratory waterfowl, songbirds, and raptors, for a large portion of the 
Central Valley's population of greater sandhill cranes, and for rare 
reptiles and mammals like the endangered giant garter snake and the 
river otter. These areas provide habitat for migratory waterfowl and 
other avian species that aid in the dispersal of vernal pool tadpole 
shrimp and other vernal pool crustacean cysts.
    Several large, diverse, vernal pool landscapes are protected within 
this unit including the Howard Ranch, and Valensin Ranch. The Clay 
Station Mitigation Bank, Laguna Creek Mitigation Bank, and the Borden 
Ranch Mitigation site are included in this unit, as well as a number of 
smaller conservation areas including the Rancho Seco Preserve. The 
conservation areas contained within this unit have been established 
specifically to contribute to the survival of vernal pool tadpole 
shrimp, and to compensate for the loss of thousands of acres of vernal 
pool grassland habitats throughout the Southeastern Sacramento Valley 
vernal pool region. This area has been identified by the Sacramento 
Valley Open Space Conservancy, the CNPS, and TNC as an excellent 
example of vernal pool grasslands, supporting a rich and diverse 
community of vernal pool endemic plants and animals within Sacramento 
County. Land ownership and protection within the unit includes CDFG 
(630 ha (1,557 ac)), TNC (3,988 ha (9.970 ac)) lands and WRP easements 
(4 ha (11 ac)). Vernal pool habitats in this unit are threatened by 
urbanization from the expanding cities of Sacramento and Elk Grove. 
Conversion from grazing to other agricultural practices, particularly 
vineyards, is also a significant threat to vernal pool tadpole shrimp 
in this unit.
    This unit occupies the area south of Deer Creek and the Cosumnes 
River to just south of the Sacramento and San Joaquin County line near 
Liberty and Collier roads. The eastern boundary is the low elevation 
foothills of western Amador County. The western limit is the Sacramento 
River. This unit also coincides with Unit 19 for vernal pool fairy 
shrimp, and incorporates Unit 1 for succulent owl's-clover, and Unit 3 
for Sacramento Orcutt grass. Other sensitive species found within this 
unit include Bogg's Lake hedge-hyssop, Ahart's dwarf rush, Henderson's 
bent grass, legenere, Sanford's arrowhead, pincushion navarretia, dwarf 
downingia, California tiger salamander, western spadefoot toad, and 
California linderiella.

Unit 10, Davis Communications Annex Unit, Yolo County (192 ha (474 ac))

    This unit is proposed as critical based on the presence of vernal 
pool tadpole shrimp (CNDDB 2001) and vernal pools, swales, and other 
ephemeral wetlands and depressions of appropriate sizes and depths that 
typically become inundated during winter rains and hold water for 
sufficient lengths of time necessary for vernal pool tadpole shrimp 
incubation, reproduction, dispersal, feeding, and sheltering, but which 
are dry during the summer and do not necessarily fill with water every 
year (Yolo County 1995, Holland 1998, Yolo County Parks 2001). Vernal 
pool tadpole shrimp within this unit are found on claypan type vernal 
pools. These pools are generally larger and stay inundated for 
relatively longer periods than vernal pools on alluvial terraces or 
volcanic mudflows and lava flows. This unit contains DOD (128 ha (321 
ac)) and county owned land. Vernal pool habitats in this unit are 
currently the focus of conservation planning efforts by Yolo County 
(Yolo County Parks 2001).
    This unit coincides with Unit 2 for Colusa grass and Unit 1 for 
Solano grass. Other rare and special status species that occur in this 
unit are Baker's navarretia, western spadefoot toad, California tiger 
salamander, brittlescale, San Joaquin saltbrush, alkali milk-vetch, 
palmate-bracted bird's beak, and the Heckard's pepper grass.

Unit 11, Jepson Prairie Unit, Solano County (34,610 ha (85,521 ac))

    This unit is proposed as critical for vernal pool tadpole shrimp 
because it includes one of the largest contiguous areas of habitat 
remaining for the species (Holland 1998, Solano County 2000, Solano 
County Farmlands and Open Space 2000, CNDDB 2001). Vernal pool tadpole 
shrimp at Jepson Prairie occur in large, playa-like vernal pools which 
may be over several acres in size, including the 32 ha (80 ac) Olcott 
Lake. The species can also be found in smaller pools and hogwallow 
depressions that also occur within this unit. The Jepson Prairie area 
supports vernal pool tadpole shrimp within unusual combinations of low 
terrace and basin rim landform vernal pools on a diversity of soil 
types, maintaining a diversity of habitats for vernal pool tadpole 
shrimp.
    The relatively undisturbed, hydrologically intact condition of the 
Jepson Prairie increases the likelihood that it will continue to 
support natural vernal pool ecosystem processes and maintain suitable 
habitat conditions for vernal pool tadpole shrimp. This unit also 
provides habitat for migratory waterfowl that aid in the dispersal of 
vernal pool tadpole shrimp and other vernal pool crustacean cysts. King 
(1996) found that vernal pool tadpole shrimp within this unit were 
genetically distinct from sampled occurrences in other portions of the 
species' range, including those just a few miles to the east in 
Sacramento County.
    Jepson Prairie has long been recognized as an outstanding example 
of vernal pool ecosystems. In 1987, the NPS named Jepson Prairie a 
National Natural Landmark, a designation given to sites that provide 
high quality habitat for threatened or endangered species. Jepson 
Prairie is the target of ongoing conservation planning efforts and 
active management. As part of the UC Reserve System, this area also 
provides critical research opportunities for scientists to study vernal 
pool species, including vernal pool tadpole shrimp.
    The unit contains lands totaling 2,248 ha (901 ac) owned and 
approximately 64 ha (160 ac) administered by CDFG. Additional lands are 
owned by DOD (760 ha (1,879 ac)), California State Parks (15 ha (38 
ac)), and the State Land Commission (109 ha (273 ac)). TNC has a 
conservation easement on 623 ha (1,558 ac) within this unit, and NRCS 
holds WRP conservation easements or agreements for 436 ha (1,090 ac). 
The Jepson Prairie Preserve is jointly managed by the Solano Land Trust 
and the UC Reserve System. Vernal pool tadpole shrimp on private land 
within this unit are threatened by agricultural conversion, range 
improvement programs, landfill expansion, power plant construction, and 
utility maintenance.
    This unit is located in the southern portion of Solano County, 
southeast of Interstate 80 and the cities of Fairfield and Vacaville, 
north of Grizzly Bay and Montezuma Slough, west of the Sacramento River 
and the Solano and Sacramento county line, and south of Midway Road and 
the City of Dixon. The unit is bisected by Highway 13 and Highway 12. 
This unit is also described as Unit 16 for vernal pool fairy shrimp. 
This unit contains Unit 3 for Colusa grass, Unit 2 for Solano grass, 
Unit 3 for Conservancy fairy shrimp, and Unit 4 and portions of Unit 5 
for Contra Costa goldfields. Other rare vernal pool

[[Page 59936]]

species which occur in this unit include alkali milk-vetch, Ferris's 
milk-vetch, vernal pool small scale, dwarf downingia, Delta green 
ground beetle, Bogg's Lake hedge-hyssop, Ricksecker's water scavenger 
beetle, California linderiella, midvalley fairy shrimp, legenere, and 
California tiger salamander.

Unit 12, Suisun Marsh Area Unit, Solano County (603 ha (1,490 ac))

    This unit is proposed as critical for vernal pool tadpole shrimp 
because it contains vernal pools that support the necessary timing, 
frequency, and duration of inundation essential for vernal pool tadpole 
shrimp life history requirements including feeding, sheltering, 
reproducing, and dispersing (Levine Fricke 2000, CNDDB 2001). This unit 
is one of only two areas where vernal pool tadpole shrimp occur in the 
saline-alkaline transition zone between vernal pools and tidal marshes, 
and helps to maintain a diversity of habitat types for this species. 
All of the habitats within this unit are on private land. The primary 
threats to vernal pool habitats within this unit are alterations to 
hydrology from filling, diking, and dredging activities which may occur 
in the tidal marsh.
    This unit is located near the Suisun Marsh in southern Solano 
County, east of Montezuma Slough and west of Collinsville Road; the 
northernmost portion of this unit is bisected by Birds Landings Road. 
Portions of this unit coincide with Unit 4 for Conservancy fairy 
shrimp. This unit also contains occurrences of other rare vernal pool 
species including alkali milk-vetch and dwarf downingia.

Unit 13, Stanislaus Unit, Stanislaus, Tuolumne, Mariposa, and Merced 
Counties (9,408 ha (23,246 ac)

    This unit is proposed as critical for vernal pool tadpole shrimp 
because it contains hardpan pools that occur on soils of alluvial fans 
and terraces of appropriate sizes and depths that become inundated 
during winter rains and hold water for sufficient lengths of time 
necessary for vernal pool tadpole shrimp incubation, reproduction, 
dispersal, feeding, and sheltering, but which are dry during the summer 
and do not necessarily fill with water every year (Holland 1998, CNDDB 
2001). Vernal pool tadpole shrimp in this unit occur within numerous 
small pools and swales on mima mound topography, supported by soils 
that are typically older than those of the alluvial terraces in the 
Sacramento area. This unit contains almost 25 percent of vernal pool 
habitats found along the eastern margin of the San Joaquin Valley. King 
(1996) found that vernal pool tadpole shrimp within this unit, although 
similar to vernal pool tadpole shrimp in eastern Sacramento County, 
were genetically different from other tadpole shrimp occurrences 
sampled throughout the species' range, particularly those on the floor 
of the Central Valley.
    The Stanislaus Unit contains very high quality, hydrologically 
intact vernal pool complexes. The well-known Hickman pools in 
Stanislaus County are located within this unit. Not only does the 
Hickman pool complex contain one of the largest vernal lakes in 
California at more than 121 ha (300 ac), but it also exhibits 
tremendous biodiversity, including one of the largest concentrations of 
imperiled amphibians (Medeiros 2000). However, the watershed containing 
the Hickman vernal pools has been breached by hundreds of acres of 
orchards that have been planted upstream. While most of the watershed 
has been managed over the years in a trust of the Fred Robinson family, 
the integrity of the vernal pool ecosystem is threatened by 
agricultural development and potential biocide pollution (Medeiros 
2000).
    The Stanislaus Unit is bordered by the Stanislaus River to the 
north and Dry Creek to the south and southeast. This unit coincides 
with vernal pool fairy shrimp Unit 22. It also encompasses succulent 
owl's-clover units 3 and 4, San Joaquin Valley Orcutt grass units 1 and 
2, hairy Orcutt grass units 4 and 5, Colusa grass units 5 and 6, 
Hoover's spurge units 4 and 5, Greene's tuctoria units 8 and 9, and 
Conservancy fairy shrimp units 4 and 6. Other sensitive vernal pool 
species found within this unit include western spadefoot toad, dwarf 
downingia, California linderiella, California tiger salamander, and 
Hartweg's golden sunburst. All the land within this unit is privately 
owned.

Unit 14, San Francisco Bay Unit, Alameda and Santa Clara Counties (458 
ha (1,132 ac)

    This unit is proposed as critical habitat for vernal pool tadpole 
shrimp because it contains occurrences of the species living within 
vernal pools that are inundated for sufficient periods of time for 
vernal pool tadpole shrimp hatching, growth, and reproduction, but are 
dry during the summer to prevent the establishment of aquatic predators 
such as bullfrogs and fish (Holland 1998, CNDDB 2001). The unit 
boundary was identified based on the distribution of vernal pool 
tadpole shrimp and the presence of these primary constituent elements, 
including vernal pools mapped by Holland (1998) and vernal pool areas 
delineated by Wetlands Research Associates (1999). The southern and 
western boundaries were delineated to exclude estuarine habitats and 
urban areas visible on SPOT imagery. This unit is also designated so 
that special management actions will be taken within vernal pool 
creation areas occurring within this unit. These areas have been 
created specifically to contribute to the conservation of vernal pool 
tadpole shrimp. Monitoring and management of these created pools will 
be necessary to ensure their continued suitability for vernal pool 
tadpole shrimp. We own approximately 10 ha (24 ac) within this unit.
    This area represents the only location where vernal pool tadpole 
shrimp occur in the San Francisco Bay region. Vernal pool tadpole 
shrimp within this unit are found in a unique tidal marsh estuary area 
that represents an unusual habitat type for the species. This unit 
represents the western extent of the species range, and is disjunct 
from other vernal pool tadpole shrimp populations elsewhere within the 
species' range in central California. This unit is over 60 km (37 mi) 
from the nearest unit to the north, and over 90 km (56 mi) from the 
nearest units to the east and south. Peripheral populations such as 
these may have genetic characteristics essential to overall long-term 
conservation of the species (i.e., they may be genetically different 
than more central populations) (Lesica and Allendorf 1995).
    This unit is situated south of the cities of Fremont and Newark, 
west of Interstate 880 and north of Mud Slough. This unit is a portion 
of Unit 8B for Contra Costa goldfields. Portions of this unit occur 
within the boundaries of San Francisco Bay National Wildlife Refuge. 
This unit includes a preserve established as conservation measures for 
vernal pool tadpole shrimp as part of the Pacific Commons development 
project (Service 2000b). This subunit also supports a large population 
of the California tiger salamander.

Unit 15, Merced Unit, Merced and Mariposa Counties (71,076 ha (175,626 
ac)

    This unit is proposed as critical for vernal pool tadpole shrimp 
because it contains more documented occurrences of the species than any 
other area throughout the species range (CNDDB 2001). The vernal pool 
tadpole shrimp in this area occur in the largest block of pristine, 
high density vernal pool grasslands remaining in California (Vollmar 
1999). These vernal pools provide the primary constituent elements 
essential for the conservation of vernal pool tadpole shrimp, and

[[Page 59937]]

supports multiple large vernal pool tadpole shrimp occurrences that are 
capable of producing large numbers of cysts in good years, which is 
important for this species to survive through a variety of natural and 
environmental changes, as well as stochastic (random) events. The 
Merced Unit contains almost 15 percent of all remaining vernal pool 
habitats in the Central Valley, and 40 percent of vernal pool habitats 
along the eastern margin of the San Joaquin Valley (Holland 1998). 
Genetic analyses of vernal pool tadpole shrimp revealed that 
occurrences in this unit are genetically different from other sampled 
occurrences (King 1996). Of all occurrences studied, King (1996) found 
these to be the most highly divergent.
    The integrity of the vernal pool complexes in eastern Merced is 
seriously threatened by irrigated agriculture, upland housing 
development, and the proposed UC Merced Campus and associated 
development. Construction of facilities to educate and serve twenty-
five thousand UC students as well as faculty, staff, and their families 
within the vernal pool complexes in eastern Merced County, could have a 
major impact on vernal pool tadpole shrimp occurrences. However, the 
recent draft biological opinion for the UC Merced campus and community 
developed environmental parameters which should reduce impacts to 
vernal pool habitats. Indirect and cumulative impacts of the proposed 
1,673 ha (4,133 ac) campus and associated community may be minimized 
with the creation of a 2,036 ha (5,030 ac) preserve intended to protect 
sensitive vernal pool habitat, to be purchased with money donated by 
the Packard Foundation. Land ownership within the unit includes 
approximately 3 ha (8 ac) of BLM, and 11 ha (26 ac) of California State 
Parks. TNC has a total of 4,513 ha (11,283 ac) of conservation 
easements within this unit.
    A majority of the vernal pool habitat in the Merced Unit is in 
Merced County. The eastern edge of the unit generally follows the 
Mariposa County line. The Chowchilla River in Madera County flows along 
the southern boundary of the unit. The northern boundary parallels the 
Merced River. The entire unit is located east of Highway 99. The Merced 
Unit coincides with vernal pool fairy shrimp Unit 22, succulent owl's-
clover units 3B, Greene's tuctoria Unit 6, Conservancy fairy shrimp 
Unit 6, Colusa grass Unit 7, San Joaquin Valley Orcutt grass units 2 
and 3. Other sensitive vernal pool species found within this unit 
include the California tiger salamander, shining navarretia, dwarf 
downingia, Bogg's Lake hedge-hyssop, western spadefoot toad, California 
linderiella, and spiny-sepaled button celery (Eryngium spinosepalum).

Unit 16, Grassland Ecological Unit, Madera, Merced and Stanislaus 
Counties (55,910 ha (138,153 ac))

    This unit is proposed as critical for vernal pool tadpole shrimp 
because it supports seven percent of the known occurrences of the 
species (CNDDB 2001) within large vernal pool complexes mapped by 
Holland (1998). This is the only area where vernal pool tadpole shrimp 
occur on the floor of the San Joaquin Valley, and contains over 50 
percent of the remaining vernal pool habitats within this region 
(Holland 1998). Vernal pool tadpole shrimp within this unit occur on 
Northern Claypan vernal pools formed by a diversity of vernal pool soil 
types, including Delhi-Dello-Himar, Solano-Caypay-Willows, Rossi-
Waukena, and Lewis-Landlow soils (Silveira 2000). Many of the vernal 
pools supporting vernal pool tadpole shrimp within this unit are large 
(over several acres in size), turbid, and alkaline. All of these pool 
types provide the necessary timing and length of inundation for vernal 
pool tadpole shrimp hatching, growth, and reproduction.
    This unit boundary was drawn to include the large, intact vernal 
pool grasslands supporting hydrologically interconnected pools, swales, 
and other ephemeral wetlands and depressions within a matrix of 
surrounding uplands where vernal pool tadpole shrimp are known, as 
mapped by Holland (1998) and as visible on SPOT imagery. However, the 
16-ha (40-ac) minimum mapping unit of Holland (1998), and the 
resolution of SPOT imagery, did not allow us to exclude all 
agricultural areas from within this unit. These features, which 
comprise the vernal pool complex, contribute to the filling and drying 
of the vernal pools, and maintain suitable periods of pool inundation, 
water quality, and soil moisture for vernal pool tadpole shrimp 
hatching, growth and reproduction, and dispersal. This unit also 
provides essential habitat for migratory waterfowl that aid in the 
dispersal of vernal pool tadpole shrimp and other vernal pool 
crustacean cysts. King (1996) found that vernal pool tadpole shrimp 
occurrences within this unit, although most similar to occurrences at 
Sequoia Field in Tulare County, are genetically different from other 
vernal pool tadpole shrimp throughout the species range. The vernal 
pool tadpole shrimp in this unit genetically very different from 
sampled occurrences less than 12 km (7 mi) to the east in the foothills 
of the Sierra Nevada.
    The Grassland Ecological Unit includes Kesterson, San Luis, and 
Merced National Wildlife Refuges (13,943 ha (34, 452 ac)), CDFG lands 
(1,703 ha (4,257 ac)), CDFG administration lands (1,052 ha (2,631 ac)), 
California State Parks (1,358 ha (3,392 ac)), and WRP easements (54 ha 
(134 ac)). Together, these areas are known as the Grasslands Ecological 
Area. This area supports diverse wetland habitats including seasonally 
flooded marshlands, semi-permanent marsh, riparian habitat, wet 
meadows, vernal pools, native uplands, pastures, and native grasslands. 
Wetlands within this area, including seasonal marsh and open water 
habitats, constitute 30 percent of the remaining wetlands in 
California's Central Valley and are extremely important to Pacific 
Flyway waterfowl populations. Over 60 million duck use-day and 3 
million goose use-days occur annually in this unit. This habitat also 
supports a diversity of other migratory birds, including raptors, 
shorebirds, wading birds, and other wildlife species.
    The unit lies north of the City of Los Banos, southwest of the City 
of Merced, and is bisected by the San Joaquin River. This unit overlaps 
Unit 23 for vernal pool fairy shrimp and Unit 7 for Conservancy fairy 
shrimp. The western half of this unit also represents Unit 2 for 
longhorn fairy shrimp, and the eastern half represents Unit 8 for 
Colusa grass, and Unit 6 for Hoover's spurge. In addition to the 
species mentioned above, vernal pool smallscale, alkali milk-vetch, 
western spadefoot toad, and California linderiella are other special 
status vernal pool species present in this unit.

Unit 17, Table Mountain Unit, Fresno County (740 ha (1,829 ac))

    This unit is proposed as critical for vernal pool tadpole shrimp 
because it supports occurrences of vernal pool tadpole shrimp (CNDDB 
2001) and extensive vernal pool complexes (Holland 1998, Keeler-Wolf et 
al. 1998). The unit also contains Northern Basalt Flow vernal pools 
that provide the necessary timing, frequency, and length of inundation 
necessary for the species to hatch, mature, reproduce, and complete its 
life cycle. The basalt flow vernal pools within this unit are found on 
narrow, sinuous basalt mesas above the surrounding low-lying terrain. 
Basalt flow vernal pools are a very rare habitat type for vernal pool 
tadpole shrimp and the habitats within this unit are important for 
maintaining the range of ecological conditions in which the

[[Page 59938]]

species occurs. They typically contain small, irregularly clustered 
pools with ``flashy hydrology'' (Keeler-Wolf et al. 1998). The 
occurrences of vernal pool tadpole shrimp in this unit are genetically 
different from occurrences in other portions of the species range, 
particularly those occurring on the floor of the Central Valley (King 
1996). Big Table Mountain, an ancient basalt mesa near Millerton Lake, 
is found within this unit and is owned and managed by CDFG, TNC, BLM. 
Land ownership within the unit includes BLM (84 ha (209 ac)), CDFG 
lands (172 ha (430 ac)), and TNC conservation easements (256 ha (639 
ac)). All other lands within this unit are privately owned.
    Located in Fresno County, this unit contains vernal pool habitats 
east and south of the San Joaquin River and east of Millerton Lake. The 
unit is west of Marshall Station and North of Table Mountain Rancheria. 
This unit coincides with succulent owl's-clover Unit 6A and San Joaquin 
Valley Orcutt grass Unit 6B. Other sensitive vernal pool species found 
within this unit include the Bogg's Lake hedge-hyssop, Molestan blister 
beetle (Lytta molesta), California linderiella, California tiger 
salamander, and the western spadefoot toad.

Unit 18 A, B and C, Tulare Unit, Tulare County (3,193 ha (7,890 ac))

    This unit is proposed as critical for vernal pool tadpole shrimp 
because it supports occurrences of the species (CNDDB 2001) within 
vernal pools that provide the essential primary constituent elements 
essential for vernal pool tadpole shrimp conservation (Holland 1998). 
The unit boundary was delineated to include vernal pool tadpole shrimp 
occurrences (CNDDB 2001) and the vernal pool complexes in which they 
occur (Holland 1998). However, the 16-ha (40-ac) minimum mapping unit 
of Holland (1998), and the resolution of SPOT imagery, did not allow us 
to exclude all agricultural or developed areas from within this unit. 
Vernal pool tadpole shrimp in this area are found within pools formed 
on San Joaquin, Cometa, and Madera soils, among others. This unit 
represents the southern extent of vernal pool tadpole shrimp's range. 
The Sequoia Field occurrence was most closely related to occurrences at 
Kesterson National Wildlife Refuge, and was generally more similar to 
other occurrences on the valley floor than occurrences found on the 
eastern margin of the valley in the Sierra Nevada Foothills. However, 
King (1996) found that vernal pool tadpole shrimp within this unit were 
genetically different from other populations studied.
    These pools are the focus of ongoing conservation efforts by CDFG, 
who manage vernal pool habitats at the Stone Corral and Sequoia Field 
Ecological Reserves found within this unit. Keeler-Wolf et al. (1998) 
identified the vernal pools in these areas as ``high quality hardpan 
pools.'' Much of the area within this unit is owned by CDFG (348 ha 861 
ac)) or occurs on private land. Agricultural conversion of range or 
barren land, particularly for orchards and feed lots, as well as 
residential and commercial development, have greatly reduced the amount 
of vernal pool habitat in Tulare County and threatens remaining 
habitats on private land in this unit.
    This unit is comprised of three subunits. Subunit A is located in 
northwest Tulare County and contains vernal pool habitat located west 
of Seville. The Friant Kern Canal is north of the unit and the 
Cottonwood Creek Levee is south of the unit. Road 140 runs west of the 
unit. Subunit B contains vernal pools in northeastern Kings County and 
northwestern Tulare County. Highway 99 and St. Johns River cut through 
the unit in a southeasterly direction. Cross Creek and Cottonwood Creek 
cut through the unit in a southwesterly direction. Road 112 is east of 
the unit and the Lakeland Canal is west of the unit. The towns of 
Goshen and Visalia are south of the unit and Traver and London are 
north of the unit. Subunit C is known as Sequoia Field Unit and is 
located in northwestern Tulare County. This unit is south of County 
Road J36. Road 112 crosses through the western edge of the unit, Avenue 
352 crosses through the southern edge, and State Route 63 crosses 
through the eastern edge. The Cross Creek Unit coincides with vernal 
pool fairy shrimp Unit 26 and contains portions of San Joaquin Valley 
Orcutt grass Unit 8 and Hoover's spurge Unit 9. Other sensitive vernal 
pool species found within this unit include the California tiger 
salamander, spiny-sepaled button-celery, and western spadefoot toad.

Butte County Meadowfoam

    In proposing critical habitat units for Butte County meadowfoam, we 
evaluated the life history and current distribution of the species, the 
primary constituent elements, the threats to the species. This 
information allowed us to determine which areas are likely to 
contribute to the conservation of these species and to delineate units 
so that threats to this species might be minimized.
    Butte County meadowfoam is restricted to a single county in 
California. The species is only known from 11 extant occurrences. An 
additional two occurrences are considered extirpated. Butte County 
meadowfoam is found in four centers of concentration. One center of 
concentration is the Shippee Road area between Chico and Oroville, 
while the other three centers of concentration are in the vicinity of 
the City of Chico.
    An important consideration for designating Butte County meadowfoam 
critical habitat is to minimize the threat of habitat fragmentation. 
All of the Chico area populations have been fragmented by the 
construction of roads or canals; several of the now separate 
occurrences may well have been continuous in the past. The roads and 
canals also altered the drainage patterns at many sites, reducing their 
suitability for Butte County meadowfoam by creating conditions too dry 
or too wet for its survival (Dole 1988, Jokerst 1989, Kelley and 
Associates Environmental Sciences 1992). Although some plants still 
remained at the type locality as of 1989, the site had been severely 
degraded by grading, agricultural use, and off-road vehicles (Jokerst 
1989, Dole and Sun 1992, 2000). Several populations have been reduced 
in size by surface disturbances such as grading and removal of topsoil 
(Jokerst 1989, Service 1992a).
    Another important criterion is that critical habitat units minimize 
the potential for alterations in hydrology. Changes in hydrology 
throughout the range of Butte County meadowfoam are possible from 
developments adjacent to extant populations, from further construction 
of roads and canals, and from grading or other surface disturbances. 
Moreover, subtle hydrological changes that already have taken place are 
likely to continue reducing Butte County meadowfoam, leading to the 
eventual extirpation of populations such as one occurrence north of the 
Chico Municipal Airport.
    Special management actions may be necessary in some areas to 
promote occurrences of Butte County meadowfoam. Light grazing may help 
to control competing plant species and prevent thatch accumulation 
(Jokerst 1989). Competition from medusa head (Taeniatherum caput-
medusae) apparently has reduced population size and seed set in Butte 
County meadowfoam at the Doe Mill Preserve (Center for Natural Lands 
Management 1997), and invasion of grasses and other weedy non-native 
plants poses a potential problem at three other occurrences (CNDDB 
2002) including

[[Page 59939]]

the occurrence at the Chico airport and an occurrence in the southern 
portion of the species range near Shippee Road.

Butte County Meadowfoam Unit Review

    We conducted a regional review across the range of Butte County 
meadowfoam to evaluate and select vernal pool habitats that are 
essential to the conservation of the species and may require special 
management. Important factors we considered were the known presence of 
Butte County meadowfoam and the presence of the primary constituent 
elements essential to the conservation of the species. A specific 
description of each area is outlined below.

Unit 1, Rock Creek Unit, Butte, and Tehama Counties (6,105 ha (15,086 
ac))

    This unit is proposed as critical for Butte County meadowfoam 
because it contains the species identified by CNDDB (2002) within 
vernal pools, swales, and complexes mapped by Holland (1998) and the 
EPA (1994). These habitats contain the primary constituent elements 
necessary for the species survival and long-term conservation, 
including vernal pools on the Tuscan formation, which typically contain 
water for shorter periods of time than other types of vernal pools.
    This unit represents the northern extent of Butte County 
meadowfoam's range, and includes occurrences from the northern race of 
Butte County meadowfoam. This race is genetically different from the 
southern race (Jokerst 1989, Dole and Sun 1992), and is important to 
maintain genetic diversity within the species. An introduced occurrence 
also occurs within this unit, although this occurrence represents 
individuals thought to be of the southern race. This unit represents 
one of only four areas where Butte County meadowfoam occurs throughout 
its entire range. Each unit is likely important to allow the species to 
tolerate natural and environmental changes, as well as random 
(stochastic) events.
    The boundaries of this unit were delineated to include the 
interconnected pools, swales, and associated uplands mapped by Holland 
(1998) that contribute to the filling and drying of the vernal pools 
where the species occur, and to maintain suitable periods of pool 
inundation, water quality, and soil moisture for Butte County 
meadowfoam germination and reproduction. The majority of the lands 
included within this unit are privately owned. Urban development, 
agricultural conversion, and hydrologic disruptions or modifications 
have greatly disturbed vernal pool habitats and restricted Butte County 
meadowfoam's distribution in this unit.
    This unit for Butte County meadowfoam occupies an area north of the 
City of Chico and includes vernal pool habitats east of Highway 99 
along the Sierra foothills from near Pine Creek southeast to Rock 
Creek. This unit overlaps Unit 1 for Conservancy fairy shrimp, Unit 7 
for vernal pool fairy shrimp, and Unit 3 for vernal pool tadpole 
shrimp. All the lands within this unit are privately owned.

Unit 2, Chico Unit, Butte County (3,508 ha (8,667 ac))

    This unit is proposed as critical for Butte County meadowfoam 
because the species is present and represents a large portion of the 
species range (CNDDB 2002). Vernal pools and swales that have the 
primary constituent elements necessary for the conservation of Butte 
County meadowfoam occur throughout this unit, including vernal pool 
habitats on Tuscan-Anita soils and the Tuscan, Riverbank, Redbluff, and 
Modesto geologic formations (EPA 1994, Holland 1998, Liss 2001, CNDDB 
2001). This unit contains individuals from the northern race of the 
species, which is genetically different from the southern race (Jokerst 
1989, Dole and Sun 1992) and is important to maintain the species 
genetic diversity. This unit is also designated so that special 
management actions, such as grazing, will be taken to reduce the 
negative effects of invasion of non-natives on occurrences of Butte 
County meadowfoam. This unit is one of only four units for Butte County 
meadowfoam across its entire range. Each unit is important to allow the 
species to tolerate a variety of natural and environmental changes, as 
well as random (stochastic) events.
    The boundaries of this unit were delineated to include the 
interconnected pools, swales, and associated uplands mapped by Holland 
(1998) that contribute to the filling and drying of the vernal pools 
where the species occur, and maintain suitable periods of pool 
inundation, water quality, and soil moisture for Butte County 
meadowfoam germination and reproduction. The majority of the lands 
included within this unit are privately owned. Portions of the Chico 
County Airport are included within this unit. A protected area has been 
set up at Foothill Park. Urban development, agricultural conversion, 
and hydrologic disruptions or modifications have greatly disturbed 
vernal pool habitats and reduced Butte County meadowfoam's distribution 
throughout this unit.
    This unit for Butte County meadowfoam occupies an area directly 
northeast and adjacent to the City of Chico. The unit extends south 
from Rock Creek and the Chico Airport to near Big Chico Creek. Highway 
99 is located west of this unit. This unit is within Unit 7 for vernal 
pool fairy shrimp, and Unit 3 for vernal pool tadpole shrimp. Other 
sensitive vernal pool species found within this unit include California 
linderiella and western spadefoot toad.

Unit 3, Doe Mill Unit, Butte County (1,696 ha (4,191 ac))

    This unit is proposed as critical for Butte County meadowfoam 
because the species is found living within vernal pools that provide 
the necessary timing and duration of inundation for Butte County 
meadowfoam growth, reproduction, and dispersal, including vernal pools 
underlain by the Tuscan geologic formation on Igo-Redding soils (EPA 
1994, Holland 1998, Liss 2001, CNDDB 2001). This unit is also 
designated so that special management actions, including grazing or 
other forms of thatch removal, will be taken to reduce the negative 
effects of invasion of non-natives on occurrences of Butte County 
meadowfoam. Plants within this unit are of the southern race of Butte 
County meadowfoam (Jokerst 1989, Dole and Sun 1992) and comprise a 
significant portion of the species genetic diversity.
    The Doe Mill Preserve (6 ha (15 ac)), managed by the City of Chico, 
is within this unit. Approximately 8.8 ha (22 ac) are public lands 
owned by the USFS. The remaining lands within this unit are privately 
owned. Urban development, agricultural conversion, and hydrologic 
disruptions or modifications have greatly disturbed vernal pool 
habitats and Butte County meadowfoam occurrences throughout this unit. 
The distribution of the species and vernal pool habitats within the 
Chico area have become highly fragmented and isolated from each other.
    The boundaries of this unit were delineated to include the 
interconnected pools, swales, and associated uplands mapped by Holland 
(1998) that contribute to the filling and drying of the vernal pools 
and swales where the species occur, and maintain suitable periods of 
pool inundation, water quality, and soil moisture for Butte Count 
meadowfoam germination and reproduction. This unit occupies an area 
directly southeast and adjacent to the City of Chico. This unit is 
within Unit 9 for vernal pool fairy shrimp, and Unit 4 for vernal pool 
tadpole shrimp.

[[Page 59940]]

Unit 4, Oroville Unit, Butte County (5,011 ha (12,382 ac))

    This unit is proposed as critical for Butte County meadowfoam 
because it contains vernal pools and swales on the Tuscan, Red Bluff 
and Riverbank geologic formations where the species is found (EPA 1994, 
Holland 1998, Liss 2001, CNDDB 2001). This unit contains individuals 
from the southern race of Butte County meadowfoam and represents an 
important component of the species genetic diversity. This unit also 
represents the southern extent of Butte County meadowfoam's range. The 
``Shipee Site'' has been described as the type locality for the species 
and is located within this unit. This unit is also designated so that 
special management actions, such as grazing, will be taken to reduce 
the negative effects of invasion of non-natives on occurrences of Butte 
County meadowfoam. This unit represents one of only four units for 
Butte County meadowfoam across its entire range. All four of these 
units are essential for the species to endure through a variety of 
natural and environmental changes, as well as random (stochastic) 
events.
    The lands included within this unit are privately owned. Urban 
development, highway expansion and construction, agricultural 
conversion, and hydrologic disruptions or modifications have greatly 
impacted vernal pool habitats and restricted Butte County meadowfoam's 
distribution throughout this unit. The distribution of the species and 
vernal pool habitats within the Chico area have become highly 
fragmented and isolated from each other.
    The boundaries of this unit were delineated to include the 
interconnected pools, swales, and associated uplands mapped by Holland 
(1998) that contribute to the filling and drying of the vernal pools 
where the species occur, and maintain suitable periods of pool 
inundation, water quality, and soil moisture for Butte County 
meadowfoam germination and reproduction. This unit occupies an area 
northwest of the City of Oroville. The unit is located south of Dry 
Creek near State Route 70 southeast to the Thermalito Diversion Pool. 
This unit is within Unit 4 for vernal pool tadpole shrimp, and 
encompasses part of Unit 5 for Greene's tuctoria.

Contra Costa Goldfields

    In proposing critical habitat units for Contra Costa goldfields, we 
evaluated the life history and current distribution of the species, the 
primary constituent elements, and the current threats to the species. 
This information allowed us to determine which areas are essential to 
the conservation of this species and to delineate units so that threats 
to this species might be minimized.
    Of the 30 occurrences of Contra Costa goldfields that were 
documented between 1884 and 1999, 19 are probably extant. The 
uncertainty is due in part to the difficulty of relocating sites based 
on vague descriptions. In addition, this species may reappear on a site 
after several years even if it is absent during a given survey. Contra 
Costa goldfields is known from disjunct locations in the coastal 
regions of California. By far the greatest concentration of this 
species is in the area east of Fairfield in Solano County. Additional 
occurrences are extant at Fort Ord in Monterey County, the San 
Francisco Bay National Wildlife Refuge and near Fremont in Alameda 
County, near Rodeo in Contra Costa County, near Manchester in Mendocino 
County, and at Suscol Ridge and Milliken Canyon in Napa County (CNDDB 
2001).
    Urban and residential development are believed to be responsible 
for the loss of at least four Contra Costa goldfields occurrences east 
of San Francisco Bay. Although the original collection sites cannot be 
pinpointed from the descriptions given on specimen labels, the areas in 
question (Antioch, Concord, Newark, San Jose, and Walnut Creek) are 
highly developed. One site in Fremont (near Newark) was degraded by 
cultivation and operation of a racetrack, but Contra Costa goldfields 
reappeared approximately a decade after the fields were abandoned (Baye 
in litt. 2000a). Urbanization is presumed to have extirpated one or 
more occurrences near Santa Barbara. One Napa County occurrence was 
destroyed by conversion to a vineyard. At least four former occurrence 
sites in Solano County have been degraded by surface disturbances, 
including discing and creek channelization, which removed some habitat, 
altered the hydrology, and allowed invasion of non-native, upland 
plants. Contra Costa goldfields has not grown at three of these sites 
during the past 10 years (CNDDB 2002).
    Urbanization is the greatest threat to Contra Costa goldfields. 
Except for Travis Air Force Base, the entire concentration area in 
Solano County is in the Fairfield sphere of influence and is subject to 
development under the city's general plan. Development also threatens 
one of the two remaining Alameda County/San Francisco Bay occurrences. 
Another serious threat is conversion to vineyards. The largest Napa 
County occurrence, at Suscol Ridge (CNDDB 2001), is threatened by 
vineyard conversion.
    Invasion of non-native plants, particularly Italian ryegrass, 
threatens at least eight occurrences, several of which are also 
targeted for development (CNDDB 2001). Encroachment by non-native 
plants often follows surface-disturbing activities such as discing, 
grading, filling, and off-road vehicle use, which can alter hydrology 
and microhabitat conditions. Such surface disturbances are apparent at 
nine sites, four of which do not yet have reported problems with non-
native species (CNDDB 2001). The CNDDB (2001) cites livestock grazing 
as a threat to seven occurrences. However, grazing may help to control 
invasion of non-native plants under certain conditions. Contra Costa 
goldfields persisted through horse grazing on Travis Air Force Base, 
but several small colonies disappeared when horses were excluded. Even 
moderately heavy grazing can be compatible with Contra Costa goldfields 
if it is suspended during critical growth periods. Occurrences of 
Contra Costa goldfields in the Fort Ord area of Monterey County exist 
at locations that have or potentially contain ordinance and explosives 
that are byproducts of military training activities. Efforts at the 
former military base have been underway to remove and dispose of these 
items. Clearance of ordinance and explosives may involve selectively 
removing vegetation, digging to expose buried objects, burning, and 
clearing of the ground surface. Project personnel have and will 
continue to implement measures that are designed to minimize and 
mitigate adverse effects to Contra Costa goldfields as ordinance and 
explosive removal activities proceed, but a potential exists that some 
plants and habitat may be affected by the clean up activities.

Contra Costa Goldfields Unit Review

    We conducted a regional review across the range of Contra Costa 
goldfields to evaluate and select areas that are essential to the 
conservation of the species and that may require special management. 
Important factors we considered were the presence of the species and 
the primary constituent elements essential to the conservation of the 
species. A specific description of each area is outlined below.

Unit 1, Manchester Unit, Mendocino County (1,067 ha (2,637 ac))

    This unit is proposed as critical habitat for Contra Costa 
goldfields because it contains the last known occurrence of Contra 
Costa goldfields in Mendocino County and is the northern

[[Page 59941]]

and western limit of the species range (CNDDB 2002). Vernal pools in 
which Contra Costa goldfields are found occur on Crispin loam soils, 
which provide the necessary timing and length of inundation to meet the 
life history requirements of Contra Costa goldfields. This is also the 
only location where Contra Costa goldfields is found on this soil type.
    This unit represents the only occurrence of Contra Costa goldfields 
in the Mendocino coast area. This unit is over 140 km (87 mi) from the 
closest Contra Costa goldfields unit to the south. Peripheral 
populations such as this may have genetic characteristics essential to 
the overall long-term conservation of the species (i.e., they may be 
genetically different from more central populations) (Lesica and 
Allendorf 1995).
    The boundaries of this unit were delineated by using SPOT imagery 
and elevation contours to include the open flat areas associated with 
the vernal pool habitat and associated uplands that contribute to the 
filling and drying of the vernal pools where the Contra Costa 
goldfields occur. The unit includes area sufficient to maintain 
suitable periods of pool inundation, water quality, and soil moisture 
for Contra Costa goldfields to germinate, grow, and reproduce.
    This unit is on private land and threats to this unit include 
conversion to vineyards, erosion, draining, and residential 
development. This unit is located in the vicinity of the town of 
Manchester just north of the Garcia River and east of the Pacific 
Ocean. State Highway 1 bisects this unit and Brushy Creek forms the 
northern and northeastern boundary of the unit.

Unit 2, Berryessa Unit, Napa County (411 ha (1,016 ac))

    This area is proposed as critical habitat for Contra Costa 
goldfields because the species is found (CNDDB 2002) within rock 
outcrops pools on soils derived from Rhyolite lava flows, within 
chaparral ecosystems (Holland 1998, USDA 2001, CNDDB 2002). These pools 
provide the necessary primary constituent elements essential for the 
conservation of Contra Costa goldfields. This is the only unit where 
Contra Costa goldfields occurs on Northern Basalt Flow vernal pools, 
and this area is important to maintain the range of habitats in which 
the species is known to occur.
    The boundaries of this unit were delineated by using SPOT imagery, 
elevation contours, and CNDDB (2002) data which identified Northern 
Basalt Flow vernal pool habitat within the unit. The unit includes the 
open flat areas associated with the vernal pool habitat and associated 
uplands that contribute to the filling and drying of the vernal pools 
where the Contra Costa goldfields occur. The unit includes area 
sufficient to maintain suitable periods of pool inundation, water 
quality, and soil moisture for Contra Costa goldfields to germinate, 
grow, and reproduce.
    This unit represents some of the last remaining vernal pool 
habitats in the north bay foothills, and is the only unit for Contra 
Costa goldfields in this area. This unit is over 25 km (15 mi) from the 
nearest Contra Costa goldfields unit.
    This unit is located south of Lake Berryessa and lies in the 
Milliken Canyon area east of the City of Yountville and northeast of 
the City of Napa. Other sensitive vernal pool species found within this 
unit include dwarf downingia, and few-flowered navarretia. All the 
lands within this unit are privately owned.

Unit 3, Napa River Unit, Napa and Sonoma Counties (275 ha (678 ac))

    This unit is proposed as critical for Contra Costa goldfields 
because the species is found within vernal pool habitats that support 
the primary constituent elements essential to the conservation of 
Contra Costa goldfields (CNDDB 2002). This unit is located on private 
land, including the Suscol Ridge area, which is threatened by vineyard 
conversion. This unit is located directly east of the Napa River 
adjacent to the salt marsh areas of the lower Napa River. Other rare 
vernal pool species found in this unit include alkali milk-vetch.

Unit 4, Travis and Fairfield Unit, Solano County (7,885 ha (19,484 ac))

    This unit is proposed as essential for the conservation of Contra 
Costa goldfields because it contains 30 percent of the known 
occurrences of this species within vernal pools in alkaline and saline-
alkaline sites, as well as those on San Ysidro and Antioch soil series 
(Holland 1998, USDA 2001, Solano County 1999, CNDDB 2002). The unit 
boundary was delineated to include Contra Costa goldfields occurrences 
and the vernal pool complexes in which they occur. These complexes 
contribute to the filling and drying of Contra Costa goldfields 
habitats, and maintain suitable periods of pool inundation, water 
quality, and soil moisture for Contra Costa goldfields germination, 
growth and reproduction, and dispersal, but not necessarily every year. 
The eastern boundary of this unit was identified by the Elmira 
watershed boundary to exclude vernal pool habitats in the Jepson 
Prairie area that are outside the currently known range of Contra Costa 
goldfields.
    This unit is located primarily on private land, but also includes 
DOD property at Travis Air Force Base (1,931 ha (4,828 ac)), CDFG land 
(117 ha (292 ac)), and State Land Commission Property (4 ha (9 ac)). 
Conservation areas have been established for Contra Costa goldfields at 
Travis Air Force Base, and these occurrences are the subject of on-
going research projects addressing the restoration and management of 
this and other vernal pool species and their habitats. Vernal pool 
habitats within this unit are threatened by urbanization from the 
cities of Fairfield and Suisun City, and by large-scale transportation 
projects, such as Jepson Parkway. The remaining vernal pool habitats 
within the City of Fairfield and Suisun City are currently the subject 
of conservation planning efforts by local agencies.
    This unit occurs in the southern portion of Solano County, 
northeast of the City of Fairfield, southwest of the City of Vacaville, 
and north of the Potrero Hills and Nurse Slough. This unit overlaps 
with Unit 3 for Conservancy fairy shrimp, and is a portion of Unit 11 
for vernal pool tadpole shrimp and Unit 16 for vernal pool fairy 
shrimp. Other rare vernal pool species which occur in this unit include 
alkali milk-vetch, legenere, and California tiger salamander.

Unit 5 A and B, Suisun Marsh Area Unit, Solano County (411 ha (1,014 
ac))

    This unit is proposed as critical habitat for Contra Costa 
goldfields because it contains occurrences of the species within vernal 
pools in the saline-alkaline transition zone between vernal pools and 
tidal marshes on Rincon soil series (USDA 1994, CNDDB 2002). The 
boundaries of this unit includes the vernal pool complexes mapped by 
Holland (1998) and the grassland habitats mapped by Solano County 
(2001) where Contra Costa goldfields occurs (CNDDB 2001). These 
habitats provide the necessary timing and length of inundation for 
Contra Costa goldfields germination, maturation, reproduction, and 
dispersal (CNDDB 2001).
    The primary threats to Contra Costa goldfields habitats within this 
unit are alterations to hydrology from filling, diking, and dredging 
activities which may occur in the tidal marsh. Most of the habitats 
within this unit are on private land, although portions of the Hill 
Slough Wildlife Area managed by the CDFG are also included within this 
unit. Subunits in the vicinity of

[[Page 59942]]

Fairfield and Suisun City are also threatened by urbanization.
    This unit consists of two subunits in the Suisun Marsh area of 
southern Solano County. Subunit 5A is the westernmost subunit and is 
located south and east of the City of Cordelia and the junction of 
Interstate Highways 80 and 680; this subunit is bisected by the 
Southern Pacific Railroad line. Subunit 5B is located southwest of the 
City of Fairfield and west of the City of Suisun City; this subunit is 
bisected by the Southern Pacific Railroad line. In addition to vernal 
pool fairy shrimp and vernal pool tadpole shrimp, this unit contains 
occurrences of other rare vernal pool species including alkali milk-
vetch and dwarf downingia.

Unit 6, Rodeo Creek Unit, Contra Costa County (243 ha (599 ac))

    This unit is proposed as critical habitat for Contra Costa 
goldfields because it supports occurrences of the species within vernal 
pool habitats formed on Conejo clay loam soils (USDA 2001, CNDDB 2002). 
The unit boundary was delineated to include the features that 
contribute to the filling and drying of the vernal pools where Contra 
Costa goldfields occurs, and that maintain suitable periods of pool 
inundation, water quality, and soil moisture for Contra Costa 
goldfields' germination, growth and reproduction, and dispersal, but 
not necessarily every year. It is the only area where the species 
occurs in the vicinity of the Sacramento-San Joaquin delta. This unit 
is over 25 km (16 mi) from the closest unit to the north, and almost 50 
km (32 mi) from the closest unit to the south.
    This unit is situated along Rodeo Creek and adjacent to State 
Highway 4. The unit lies southeast of the City of Rodeo and northeast 
of the City of Hercules. The unit contains a 3.94 ha (9.74 ac) 
conservation easement area established in 1999 to protect three known 
locations of Contra Costa goldfields along Rodeo Creek from highway 
construction activities along State Route 4. Other rare species which 
occur in this unit include the federally threatened California red-
legged frog and another sensitive species, the western pond turtle 
(Clemmys marmorata). All the lands within this unit are privately 
owned.

Unit 7, Byron Hot Springs Unit, Contra Costa County (1,379 ha (3,406 
ac))

    This unit is proposed as critical habitat for Contra Costa 
goldfields because it contains the only remaining extant occurrence of 
Contra Costa goldfields in southeastern Contra Costa County (CNDDB 
2001). This occurrence within vernal pools formed on Linne clay loam 
soils, and has been characterized as alkaline meadow (USDA 2001, CNDDB 
2002). This habitat provides the timing and frequency of inundation 
essential to the germination, growth, and reproduction of Contra Costa 
goldfields, and this area includes a unique habitat type for this 
species. The unit boundary includes vernal pool complexes mapped by 
Holland (1998) where Contra Costa goldfields is known to occur (CNDDB 
2002). This unit is over 35 km (22 mi) from the closest unit to the 
north, and almost 50 km (32 mi) from the closest unit to the south.
    This unit is in the vicinity of Byron Hot Springs and Byron Airport 
and lies directly west of Clifton Court Forebay. This unit mostly 
includes habitat in low-lying areas east of Altamont Hills, but also 
includes habitat within a small portion of Altamont Hills. A small 
portion of this unit overlaps with Unit 19B for vernal pool fairy 
shrimp. Approximately 232 ha (581 ac) within this unit are owned by the 
CDFG and 55 ha (137 ac) are owned by the State Land Commission the rest 
is privately owned.

Unit 8, Southeastern San Francisco Bay Unit, Alameda and Santa Clara 
Counties (458 ha (1,132 ac))

    This unit is proposed as critical for Contra Costa goldfields 
because it contains occurrences of this species within vernal pools, 
swales, moist flats, and other ephemeral wetlands in saline alkaline 
transition zones with tidal marsh habitats that sustain Contra Costa 
goldfields germination, growth and reproduction (CNDDB 2002, Holland 
1998). The unit boundary was identified based on the distribution of 
Contra Costa goldfields and the presence of these primary constituent 
elements, including vernal pools mapped by Holland (1998) and vernal 
pool areas delineated by Wetland Research Associates (1999). The 
southern and western boundaries were delineated to exclude estuarine 
habitats and urban areas visible on SPOT imagery.
    This unit contains a 180 ha (450 ac) preserve established 
specifically to contribute to the recovery of Contra Costa goldfields 
(Service 2000b, Wetland Research Associates 1999) and 443 ha (1,108 ac) 
of this unit is owned by the Service. This unit is over 50 km (31 mi) 
from the nearest units to the north, and almost 100 km (62 mi) from the 
nearest Contra Costa goldfields unit to the south.
    This unit occurs in southeastern San Francisco Bay and also 
represents Unit 14 for vernal pool tadpole shrimp. The unit lies 
between the northernmost and southernmost subunits and is situated 
south of the cities of Fremont and Newark and north of Mud Slough. 
Portions of this unit is found within the boundaries of San Francisco 
Bay National Wildlife Refuge and the rest is privately owned.

Unit 9, Fort Ord Unit, Monterey County (3,372 ha (8,331 ac))

    The Fort Ord unit includes seasonally flooded pool habitats and 
mima mound grassland areas that are within the boundary of an area that 
was previously managed as the Fort Ord Army Base. These lands are now 
or will be managed by a number of Federal and local governments 
following a transfer from the DOD. Approximately 2,894 ha (7,234 ac) of 
this unit are currently owned by the DOD, 437 ha (1,093 ac) by BLM, and 
2 ha (4 ac) by Monterey County. The critical habitat unit includes a 
number of seasonally-flooded wetland habitats and at least four 
locations that possess Contra Costa goldfields. Monitoring activities 
at two of the four locations suggest that listed plant numbers vary on 
an annual basis, and that differences in species abundance may be 
attributable to differences in annual rainfall totals and water 
duration in ponded areas (Harding Lawson Associates 2001). The total 
combined population estimates for the two areas where monitoring 
occurred in 1998, 1999, and 2000 were 500-1500, 56,000, and 162,500 
individuals, respectively. The areas on the former military base that 
contain Contra Costa goldfields are being transferred to the BLM as a 
habitat reserve Natural Resource Management Area. Contra Costa 
goldfields in Monterey County are located 60 miles south of other 
locations where the species has been documented. This unit is essential 
to the conservation of Contra Costa Goldfields because it contains the 
southern-most extant occurrence of the species.

Hoover's Spurge Criteria

    In proposing critical habitat units for Hoover's Spurge we 
evaluated the life history and current distribution of the species, the 
primary constituent elements, and the current threats to the species. 
This information allowed us to determine which areas are likely to 
contribute to the conservation of these species.
    The CNDDB (2001) includes 30 occurrences of Hoover's spurge, six of 
which were discovered in 1992 (three each in Glenn and Tulare 
counties). Of the 30 occurrences, one each in Tehama and Tulare 
counties are classified as extirpated; two others, in Butte and

[[Page 59943]]

Tehama counties, are ``possibly extirpated'' because this species was 
not observed for 2 consecutive years (Stone et al. 1988, CNDDB 2001). 
Of the 26 occurrences presumed to be extant, only 12 have been observed 
within the past decade (CNDDB 2001).
    The main area of concentration for Hoover's spurge is within the 
Vina Plains area of Tehama and Butte counties, which contains over half 
of the 26 presumed extant occurrences for Hoover's spurge (CNDDB 2001). 
One other site in the same region is near Chico in Butte County. Other 
extant occurrences of the species are found in the Visalia-Yettem area 
of Tulare County, the Hickman-La Grange area of Stanislaus County, the 
Sacramento National Wildlife Refuge in Glenn County, and on the Bert 
Crane Ranch in Merced County (CNDDB 2001).
    One population of Hoover's spurge in Tulare County and another in 
Tehama County were destroyed when the areas were converted for 
agricultural use (CNDDB 2002). Agricultural conversion continues to 
threaten Hoover's spurge, particularly in Stanislaus County (Stone et 
al. 1988). However, more subtle factors such as changes in hydrology, 
invasion by aggressive plants, and inappropriate livestock grazing 
regimes constitute a greater threat to survival of the species at this 
time. Five of the remaining occurrences of Hoover's spurge are subject 
to obvious hydrologic threats; four of the five are in the San Joaquin 
Valley and the fifth is in the Vina Plains. Hydrology has been altered 
by (1) construction of levees and other water barriers and (2) by 
runoff from adjacent agricultural operations, roads, and culverts. Due 
to these changes, some pools receive insufficient water and others 
remain flooded for too long to allow growth of Hoover's spurge. 
Although no occurrences have been completely extirpated due to 
hydrologic changes, the species has been eliminated from one or more 
individual pools at several sites and a number of the remaining 
populations appear to be declining (Stone et al. 1988, Stebbins et al. 
1995, CNDDB 2002).
    Competition from invasive native or non-native plant species 
threatens nine of the extant occurrences, including eight in the Vina 
Plains and one on the Sacramento National Wildlife Refuge in Glenn 
County. Native competitors of Hoover's spurge include coyote-thistle, 
alkali mallow (Malvella leprosa, a noxious weed according to Hill 
1993), lippia (Phyla nodiflora), hard-stemmed tule (Scirpus acutus var. 
occidentalis), alkali bulrush (Scirpus maritimus), and cocklebur. Non-
native competitors include bindweed (a noxious weed according to 
Dempster 1993) and swamp grass (Crypsis schoenoides) (Silveira in litt. 
2000, CNDDB 2001). On the Vina Plains Preserve, the pools with Hoover's 
spurge also had the highest frequency of bindweed, at least in 1995 
(Alexander and Schlising 1997). Increasing dominance by these 
competitors may be associated with changes in hydrology and livestock 
grazing practices (Stone et al. 1988, Alexander and Schlising 1997, 
CNDDB 2002).
    The issue of livestock grazing effects on Hoover's spurge is 
complex. In general, moderate levels of grazing appear to be compatible 
with Hoover's spurge and presumably benefit the species by reducing 
competition from other plants (Stone et al. 1988). Livestock do not eat 
Hoover's spurge because it grows so close to the ground and possibly 
because the milky sap is toxic (Wheeler 1941, Stone et al. 1988). 
During 1986 and 1987, Stone et al. (1988) deemed the intensity of 
cattle grazing at most Hoover's spurge sites to be appropriate. In 
fact, several species experts (Stone et al. 1988, Silveira in litt. 
2000) have cautioned that decreases in grazing intensity could be 
detrimental to Hoover's spurge. On the other hand, cattle trampling has 
seriously reduced Hoover's spurge populations at one site each in Butte 
and Stanislaus counties (Stone et al. 1988), and increased summer 
stocking rates at other sites could similarly damage those populations.
    Populations with small numbers of plants may be more vulnerable to 
extirpation from random events (Shaffer 1981, Menges 1991). This may be 
the case for at least four of the known occurrences, which total fewer 
than 100 individuals even in favorable years (CNDDB 2002).

Hoover's Spurge Unit Review

    We conducted a review across the range of Hoover's spurge to 
evaluate and select areas that are essential to the conservation of the 
species and that may require special management. Important factors we 
considered were the documented presence of the species and the presence 
of the primary constituent elements essential to the conservation of 
the species. A specific description of each area is outlined below.

Unit 1, Vina Plains Unit, Tehama and Butte Counties (11,673 ha (28,845 
ac))

    This unit is proposed as critical for Hoover's spurge because it 
supports numerous occurrences of the species within vernal pools on 
acidic soils over iron-silica cemented hardpan, including Anita and 
Tuscan soils (USDA 2001, Holland 1998, CNDDB 2002). The Vina Plains 
Unit contains over 50 percent of the known occurrences of Hoover's 
spurge, including several large, stable occurrences (CNDDB 2002). This 
area represents the northern extent of the species range.
    The boundaries of this unit were delineated to include the 
interconnected pools, swales, and associated uplands mapped by Holland 
(1998) that contribute to the filling and drying of the vernal pools 
where the species occur, and maintain suitable periods of pool 
inundation, water quality, and soil moisture for Hoover's spurge 
germination and reproduction.
    The majority of the lands included within this unit are privately 
owned. This unit contains TNC's 1862 ha (4,600 ac) Vina Plains 
preserve. The preserve contains over 300 species of plants and diverse 
communities of aquatic invertebrates. Since the 1960s, the Vina Plains 
area has been the focus of a number of research projects, including 
long-term adaptive management and monitoring efforts evaluating of the 
effects of grazing and fire on vernal pool plants (Griggs 2000). Much 
of the basic life history information known about Hoover's spurge was 
collected at Vina Plains (e.g., Stone et al. 1988, Alexander and 
Schlising 1997). The results of this research have provided crucial 
information to guide management and monitoring of vernal pool 
ecosystems and to identify factors which influence population dynamics 
of a number of endangered species.
    The Vina Plains is open to the public and provides excellent 
outreach and educational opportunities. In addition to TNC, the 
importance of vernal pool habitats in this area has been recognized by 
the CDFG, the Service, the EPA, the CNPS, the NRCS's WRP, and by 
researchers at the CSU at Chico, who have all supported research and 
conservation efforts for Hoover's spurge and other vernal pool species 
within this unit. Urban development north of Chico and the conversion 
of grazed lands to more intensive agricultural uses threaten vernal 
pool habitat within this unit.
    This unit for Hoover's spurge occupies the area south of Toomes 
Creek and north of Pine Creek to near Cana Highway. State Route 99 
bisects this unit and the western boundary generally parallels the 
Southern Pacific Railway line. This unit overlaps Unit 7 for vernal 
pool fairy shrimp, Unit 3 for vernal pool tadpole shrimp, Unit 1 for 
Conservancy fairy shrimp, Unit 2 for Greene's tuctoria, Unit 1 for 
Hoover's spurge, and Unit 4 for slender Orcutt grass. Additional 
sensitive vernal pool

[[Page 59944]]

species occurring in this unit include California linderiella and 
Bogg's Lake hedge-hyssop. Property ownership and protection within this 
unit includes CDFG (0.4 ha (1 ac)), CDFG administration (0.4 ha (1 
ac)), TNC (2,295 ha (5,738 ac)), TNC easements (4,661 ha (11,653)), and 
WRP easements and agreements (57 ha, 142 ac)).

Unit 2, Butte Unit, Butte County (979 ha (2,418 ac))

    This unit is proposed as critical habitat for Hoover's spurge 
because it supports the species within vernal pools on acidic Tuscan 
soils over iron-silica cemented hardpan (CNDDB 2002, Liss 2001, USDA 
2001, Holland 1998, EPA 1994) and the vernal pool habitat remains 
inundated for sufficient periods of time to allow Hoover's spurge to 
complete its life-cycle. This unit represents one of only three areas 
where Hoover's spurge is known to occur in the Sacramento Valley, and 
is over 225 km (140 mi) from the nearest occupied areas to the south.
    The boundaries of this unit were delineated to include the 
interconnected pools, swales, and associated uplands mapped by Holland 
(1998) that contribute to the filling and drying of the vernal pools 
where the species occur, and maintain suitable periods of pool 
inundation, water quality, and soil moisture for Hoover's spurge 
germination and reproduction. Hoover's spurge is known from only seven 
general locations across its entire range, and each of these locations 
is essential to the conservation of this species.
    This unit for Hoover's spurge occupies the area north of the 
intersection of State Route 99 and Route 149 in Butte County. The 
eastern boundary extends up the watershed of Clear Creek and the 
western boundary extends south paralleling State Route 99 to Little Dry 
Creek. This unit is within Unit 9 for vernal pool fairy shrimp and Unit 
4 for vernal pool tadpole shrimp, and coincides with Unit 3 for 
Greene's tuctoria and Units 2 and 3 for hairy Orcutt grass. All the 
land within this unit is privately owned.

Unit 3, Sacramento National Wildlife Refuge Unit, Glenn and Colusa 
Counties (5,718 ha (14,129 ac))

    This unit is proposed as critical habitat for Hoover's spurge 
because it contains multiple occurrences of the species within alkaline 
vernal pools on Willows and Riz soil types (Holland 1998, Silveira 
2000, CNDDB 2002). The vernal pool habitat remains inundated for 
sufficient periods of time to allow Hoover's spurge to complete its 
life cycle. This habitat contributes to the diversity of environmental 
conditions in which Hoover's spurge is known to occur. This area 
represents one of only three general locations where Hoover's spurge is 
found in the Sacramento Valley, and is one of only seven areas across 
its entire range where Hoover's spurge is known to occur. This unit is 
over 40 km (25 mi) from the nearest unit to the northeast, and over 225 
km (140 mi) from the nearest unit to the south. Hoover's spurge 
occurrences at the Sacramento National Wildlife Refuge have been 
monitored annually since 1992 (Silveira in litt. 2000).
    The boundaries of this unit were delineated to include the 
interconnected pools, swales, and associated uplands mapped by Holland 
(1998) that contribute to the filling and drying of the vernal pools 
where the species occur, and maintain suitable periods of pool 
inundation, water quality, and soil moisture for Hoover's spurge 
germination and reproduction to take place.
    This unit for Hoover's spurge occupies the vernal pool habitat and 
surrounding area east of Interstate 5 to the Colusa Trough from Riz 
Road on the north and Delevan Road on the south. The area encompasses a 
portion of the Sacramento National Wildlife Refuge (5,126 ha (12,816 
ac)). The remaining portions of the unit are privately owned. This unit 
is also part of vernal pool fairy shrimp Unit 10, and vernal pool 
tadpole shrimp Unit 5, and coincides with Unit 2 for Conservancy fairy 
shrimp, Unit 1 for Greene's tuctoria, and Unit 3 for hairy Orcutt 
grass. Other vernal pool and associated upland species found in the 
unit include pappose spikeweed, Fremont's goldfields, alkali 
goldfields, Scribe's popcorn flower, Hoover's downingia, folded 
downingia, Heckard's peppergrass, heartscale, brittlescale, San Joaquin 
spearscale, Ferris' milk-vetch, spike-primrose, sessile mousetail, and 
palmate-bracted bird's beak.

Unit 4, Waterford Unit, Stanislaus and Tuolumne Counties (16,839 ha 
(41,609 ac))

    This unit is proposed as critical habitat for Hoover's spurge 
because it supports the species within vernal pools on Whitney sandy 
loam soils that maintain the necessary timing and duration of 
inundation for Hoover's spurge germination, growth, and reproduction 
(USDA 2001, CNDDB 2002). This unit contains soils that are typically 
older than those of the alluvial terraces in the Sacramento area which 
are estimated to be early Pleistocene.
    The Waterford Unit contains very high quality, hydrologically 
intact vernal pool complexes important for the conservation of Hoover's 
spurge. Hoover's spurge is sparsely distributed in the southern Sierra 
Nevada foothills, and these occurrences are highly disjunct from the 
occurrences of Hoover's spurge in the northern portion of the species 
range. This unit is over 225 km (140 mi) from the nearest units to the 
north. The largest threat to Hoover's spurge in this unit is 
agricultural conversion (Stone et al. 1988). Cattle trampling has also 
impacted an occurrence of Hoover's spurge in the southeastern region of 
the unit (CDNNB 2001). There are numerous deep pools in this area that 
provide suitable habitat for Hoover's spurge because the duration of 
inundation is generally longer than in shallow pools. These pools 
contain habitat components that are essential for the primary 
biological needs of germination, growth, reproduction, and dispersal of 
the species.
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery, as well as elevation contours in the 
eastern foothill region and sub-watershed boundaries. The Waterford 
Unit is bordered by the Tuolumne River to the south. The Modesto 
Reservoir is adjacent to the southwest boundary of the unit. 
Warnerville Road cuts through the northern portion of the unit. The 
City of La Grange is located southeast of the unit. The eastern 
boundary extends into the low elevation foothills of the Sierra Nevada. 
Vernal pools in the Waterford Unit are located mainly in eastern 
Stanislaus County, but overlap into western Tuolumne County. This unit 
coincides with Colusa grass Unit 4, San Joaquin Valley Orcutt grass 
Unit 1, and hairy Orcutt grass Unit 4. It overlaps succulent owl's-
clover Unit 2 and Greene's tuctoria Unit 6. Other sensitive vernal pool 
species found within this unit include California tiger salamander, 
western spadefoot toad, dwarf downingia, and California linderiella. 
CDFG administers approximately 0.8 ha (2 ac) of this unit. The 
remaining land within this unit is privately owned.

Unit 5, Turlock Unit, Stanislaus and Merced Counties (19,850 ha (49,049 
ac))

    This unit is proposed as critical habitat for Hoover's spurge 
because it contains occurrences of the species within large vernal 
pools on Meikle soils, including two of the seven known occurrences of 
Hoover's spurge on the eastern margin of the San Joaquin Valley 
(Holland 1998, CNDDB 2002). One occurrence is within the well-known 
Hickman pools in Stanislaus County.

[[Page 59945]]

Not only does the Hickman pool complex contain one of the largest 
vernal lakes in California at more than 121 ha (300 ac), but it also 
exhibits tremendous biodiversity (Medeiros 2002).
    The Turlock Unit contains large intact and contiguous vernal pool 
grassland areas that help maintain connectivity between hairy Orcutt 
grass habitat to the north and south. There are numerous vernal pools, 
swales, and other ephemeral wetlands and depressions of appropriate 
sizes and depths in this unit to sustain Hoover's spurge germination, 
growth and reproduction. Hoover's spurge populations in Stanislaus 
County typically flower from mid-June into October, whereas those in 
Merced and Tulare counties typically flower from late May through July 
(Alexander and Schlising 1997). The Hoover's spurge habitat in this 
unit is important to conserve phenotypic variation within the species 
and to maintain the geographic distribution of Hoover's spurge 
throughout its range.
    The largest threat to this species in this unit is agricultural 
conversion (Stone et al. 1988). The watershed containing the vernal 
pools has been breached by hundreds of acres of orchards that have been 
planted upstream. East of the Hickman vernal pools, there is a large, 
hydrologically intact vernal pool complex that likely contains other 
occurrences of Hoover's spurge.
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery. The Turlock Unit is bordered by the 
Tuolumne River to the north and the Merced River to the south. The unit 
lies between the towns of La Grange and Snelling. County Road J9 runs 
west of the unit and the eastern edge is located in the low elevation 
foothills of the Sierra Nevada. Vernal pools in the Turlock Unit are 
located in Stanislaus and Merced counties. This unit coincides with 
Colusa grass Unit 6, hairy Orcutt grass Unit 5, succulent owl's-clover 
Unit 3A, and vernal pool fairy shrimp Unit 21. Other sensitive vernal 
pool species found within this unit include California tiger 
salamander, Hartweg's golden sunburst, and dwarf downingia. California 
State Parks owns approximately 24 ha (60 ac) within this unit. The 
remaining land within this unit is privately owned.

Unit 6, Grasslands Unit, Madera, Merced and Stanislaus Counties (14,310 
ha (35,359 ac))

    This unit is proposed as critical habitat for Hoover's spurge 
because it support occurrences of the species within saline-alkaline 
vernal pools on Lewis soils (USDA 2001, CNDDB 2002). The unit boundary 
was designated to include occurrences of Hoover's spurge and the vernal 
pool complex in which they occur (Holland 1998). The vernal pools, 
swales, and associated uplands within this unit contribute to the 
filling and drying of Hoover's spurge habitat, and maintain suitable 
periods of pool inundation, water quality, and soil moisture for 
Hoover's spurge germination, growth and reproduction, and dispersal.
    The Grasslands Unit includes portions of the Kesterson, San Luis, 
and Merced National Wildlife Refuges (3,232 ha (7,985 ac). The 
remaining land within this unit is privately owned. This unit contains 
a diversity of vernal pool types, including vernal pools occurring on 
Delhi-Dello-Himar, Solano-Caypay-Willows, Rossi-Waukena, and Lewis-
Landlow soils (USDA 1994). This unit contains the majority of the 
remaining vernal pool habitats in the San Joaquin Valley (Holland 
1998). Threats to remaining vernal pool habitats within this unit 
include agricultural conversion.
    The unit lies north of the City of Los Banos, southwest of the City 
of Merced, and is bisected by the San Joaquin River. This unit 
represents Unit 23 for vernal pool fairy shrimp, Unit 7 for Conservancy 
fairy shrimp, and Unit 16 for vernal pool tadpole shrimp. The western 
half of this unit represents Unit 8 for Colusa grass. In addition to 
the species mentioned above, vernal pool smallscale, alkali milk-vetch, 
western spadefoot toad, and California linderiella are present in this 
unit as well.

Unit 7 A, B, C, and D, Tulare Unit, Tulare County (12,375 ha (30,578 
ac))

    This unit is proposed as critical habitat for Hoover's spurge 
because it supports almost 20 percent of the known occurrences of the 
species, including occurrences found within vernal pools on Lewis soils 
(USDA 2001, CNDDB 2002). This unit comprises the southern extent of the 
range of Hoover's spurge. Occurrences within this unit are more than 
110 km (68 mi) distant from the nearest Hoover's spurge unit to the 
north. Peripheral populations may have genetic characteristics 
essential to overall long-term conservation of the species (i.e., they 
may be genetically different than more central populations) (Lesica and 
Allendorf 1995). Hoover's spurge populations in Tulare County typically 
flower from late May through July, whereas those in Stanislaus and 
Sacramento County typically flower from mid-June into October 
(Alexander and Schlising 1997). This phenotypic variation also suggests 
there may be regional differences between these and other occurrences 
in other portions of the species range.
    This unit includes several protected areas, including the Sequoia 
Fields Ecological Reserve and the Stone Corral Ecological Reserve in 
Tulare County managed by CDFG (355 ha (877 ac)) as well as 13 ha (33 
ac) of BLM land. Other areas within this unit are privately owned, and 
are threatened by conversion to irrigated agriculture of range. This 
unit contains scattered vernal pool complexes in northwestern Tulare 
County. This unit contains deeper pools that maintain suitable periods 
of pool inundation, water quality, and soil moisture for vernal pool 
plant germination, growth and reproduction, and dispersal.
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery, as well as elevation contours in the 
eastern foothill region and sub-watershed boundaries. There are four 
subunits within the Tulare Unit. The westernmost subunit is located 
east of J19. Road 63 cuts through its eastern edge. St. Johns River is 
south of the subunit and the Southern Pacific Railroad runs northeast 
of the unit. The other three subunits are located east of Road 63. The 
smallest subunit lies directly east of the westernmost subunit. Road 
201 passes through both of the easternmost subunits. The subunit that 
lies next to the easternmost subunit contains vernal pool habitat north 
of Stokes Mountain. In the south it is bordered by Cottonwood Creek. 
The easternmost subunit extends into the low elevation foothills of the 
Sierra Nevada. Colvin Mountain is located within its southwest 
boundary. Road 245 bisects this subunit and the south side of Red 
Mountain is within its northeast boundary. Tulare Unit coincides with 
San Joaquin Valley Orcutt grass Unit 7, and overlaps with vernal pool 
tadpole shrimp Unit 18 and vernal pool fairy shrimp Unit 26. Other 
sensitive vernal pool species found within this unit include the 
California tiger salamander, spiny-sepaled button-celery, and western 
spadefoot toad.

[[Page 59946]]

Succulent Owl's-clover

    In proposing critical habitat units for succulent owl's-clover we 
evaluated the life history and current distribution of the species, the 
primary constituent elements, and the threats to the species. This 
information allowed us to determine which areas are likely to 
contribute to the conservation of this species and to delineate units 
so that threats to this species might be minimized.
    Succulent owl's-clover is currently known from 63 occurrences, of 
which one in Fresno County is considered to be ``possibly extirpated'' 
(CNDDB 2002) because the site had been disced when it was last visited 
in 1981. Another site in Fresno County also may be extirpated. Among 
the areas where succulent owl's-clover is known to occur, more than 
half are in Merced County. Additional occurrences are found in Fresno, 
Madera, Stanislaus, and San Joaquin counties (CNDDB 2001).
    The current status of most succulent owl's-clover populations is 
unknown because most sites have not been visited for decades. 
Inappropriate cattle grazing and trampling degraded three occurrences 
of succulent owl's-clover. One of the same sites plus three others were 
degraded by discing. The CNDDB (2002) lists one of the latter as 
``possibly extirpated'' due to discing. However, succulent owl's-clover 
persisted at another site that had been disced, although the population 
size was reduced by an order of magnitude (CNDDB 2001).
    A wide variety of factors threaten the continued existence of 
succulent owl's-clover, including urban development, year-round or 
summer livestock grazing, changes in hydrology, agricultural 
conversion, gravel mining, and small population size. Construction of 
the proposed new UC campus in Merced County, plus the associated 
residential community and access roads, threatens the extensive 
population in that area. Different types of urban development that 
threaten numerous known occurrences include planned housing 
subdivisions in Fresno, Madera, and San Joaquin counties; a freeway 
expansion in Madera County; and a proposed landfill in Fresno County 
(Service 1997, Stebbins in litt. 2000, CNDDB 2001).
    Approximately two-thirds of the reported occurrences, including 
those at the UC Merced site, were subject to cattle grazing when they 
were discovered (EIP Associates 1999, CNDDB 2001). However, grazing is 
not necessarily detrimental to succulent owl's-clover. Winter and 
spring grazing may be helping in controlling non-native grass invasions 
(Barry 1998). Stebbins et al. (1995) noted that among the sites they 
studied, those that were grazed ``did not appear to suffer long-term 
damage due to grazing.'' Damage from livestock would be harmful when 
pools are dry and during the time that the water is evaporating; thus 
summer or year-round grazing poses a threat (Barry 1998).
    Hydrological alterations can create conditions unsuitable for 
succulent owl's-clover and other vernal pool plants by increasing or 
decreasing the depth and duration of inundation. Threats due to 
alterations in natural hydrology include the Merced County Stream 
Channel Project proposed by the U.S. Army Corps of Engineers 
(Corps)(Service 1997a) and proposed enlargement of Burns Reservoir in 
Merced County (CNDDB 2001), which collectively threaten seven 
occurrences of succulent owl's-clover. Expansion of agricultural 
operations threatens three occurrences in Fresno and Madera counties 
that are surrounded by orchards, vineyards, or citrus groves (CNDDB 
2001). Also, populations in grain fields already have been subject to 
discing, as mentioned above. A proposed gravel mine threatens one 
occurrence in Fresno County (Service 1997a).
    Threats posed by small population size are less immediate but also 
potentially significant. Random genetic, environmental, or other 
processes can lead to the extirpation of small populations; adequate 
populations would be in the range of thousands to millions (Shaffer 
1981, Thomas 1990, Menges 1991). Species that are subject to extreme 
fluctuations in population size from year to year are particularly 
vulnerable to chance events (Thomas 1990). Among the 24 populations of 
succulent owl's-clover for which size estimates were given, 10 
consisted of fewer than 100 plants at their peak size (CNDDB 2001, 
Stebbins in litt. 2000).

Succulent Owl's-Clover Unit Review

    We conducted a regional review across the range of succulent owl's-
clover to evaluate and select areas that are essential to the 
conservation of the species and that may require special management. 
Important factors we considered were the presence of the species and 
the primary constituent elements essential to the conservation of the 
species. A specific description of each area is outlined below.

Unit 1, Southeast Sacramento Valley Unit, Sacramento and San Joaquin 
Counties (1,052 ha (2,598 ac))

    This unit is proposed as critical habitat for succulent owl's-
clover because it contains occurrences of the species living within 
vernal pools occurring on San Joaquin soils that provide the necessary 
timing and length of inundation for succulent owl's-clover germination, 
growth, and reproduction (Holland 1998, Sacramento County 1999, CNDDB 
2002).
    The site is a ``Nature Study Area'' for the UC Cooperative 
Extension (CNDDB 2001). This unit represents the northern most extent 
of succulent owl's-clover range and is the only unit designated for 
this species within the Sacramento Valley. The unit is isolated from 
other succulent owl's-clover occurrences to the south in the San 
Joaquin Valley by a distance of over 80 km (50 mi). Isolated and 
peripheral populations such as this may have genetic characteristics 
essential to the overall long-term conservation of the species (i.e., 
they may be different from more central populations) (Lesica and 
Allendorf 1995).
    The boundaries of this unit were delineated to include the 
interconnected pools, swales, and associated uplands mapped by Holland 
(1998) that contribute to the filling and drying of the vernal pools 
where the species occur, and maintain suitable periods of pool 
inundation, water quality, and soil moisture for succulent owl's-clover 
germination and reproduction.
    This unit for succulent owl's-clover occupies the area east of Galt 
near Dustin and Liberty roads. All the lands included within this unit 
are privately owned. Urban expansion and conversion from grazing to 
other agricultural practices, particularly vineyards have greatly 
affected existing vernal pool habitats throughout this area. Other 
sensitive vernal pool species found within this unit includes the 
California tiger salamander.

Unit 2, Waterford Unit, Stanislaus and Tuolumne Counties (14,131 ha 
(34,917 ac))

    This unit is proposed as critical habitat for succulent owl's-
clover because it supports occurrences of the species within hardpan 
vernal pools on alluvial terraces on Amador and Redding soils that 
provide the necessary timing and length of inundation essential to the 
conservation of the species (CNDDB 2002). This is the northernmost 
extent of succulent owl's-clover's range within the San Joaquin Valley, 
and is over 80 km (50 mi) from

[[Page 59947]]

the isolated occurrence to the north. This unit contains a variety of 
pools and ephemeral habitats in which the plants are known to occur, 
including shallow and deep pools and pools with both long and short 
inundation periods. These pools contain appropriate conditions for 
germination, growth, reproduction, and dispersal of succulent owl's-
clover. The Waterford Unit is important for the survival of succulent 
owl's-clover because it represents large areas of contiguous habitat 
with relatively intact hydrology. All the lands within this unit are 
privately owned.
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery, as well as elevation contours in the 
eastern foothill region and sub-watershed boundaries. The Waterford 
Unit is bordered by the Tuolumne River to the south. The Modesto 
Reservoir is adjacent to the southwest boundary of the unit. 
Warnerville Road cuts through the northern portion of the unit. The 
City of La Grange is located southeast of the unit. The eastern 
boundary extends into the low elevation foothills of the Sierra Nevada. 
Vernal pools in the Waterford Unit are located mainly in eastern 
Stanislaus County, but overlap into western Tuolumne County. This unit 
overlaps with San Joaquin Valley Orcutt grass Unit 1, hairy Orcutt 
grass Unit 4, Colusa grass Unit 4, Hoover's spurge Unit 4, and Greene's 
tuctoria Unit 6. Other sensitive vernal pool species found within this 
unit include California tiger salamander, western spadefoot toad, dwarf 
downingia, and California linderiella.

Unit 3A and B, Merced Unit, Merced County (63,352 ha (156,542 ac))

    This unit is proposed as critical habitat for succulent owl's-
clover because it supports over 50 percent of the known occurrences of 
the species, living within vernal pools on Redding, Corning, and Pentz 
soil series that provide the primary constituent elements essential to 
the conservation of the species (CNDDB 2002). This unit represents the 
largest remaining habitat area for succulent owl's-clover, and includes 
the largest block of pristine, high density vernal pool grasslands 
remaining in California (Holland 1998, Vollmar 1999). This unit is 
important to maintain a diversity of habitats for succulent owl's-
clover, and supports hydrologically intact vernal pool complexes that 
are likely to maintain ecosystem processes important to the recovery of 
succulent owl's-clover.
    A majority of the land in this unit is privately owned, and is used 
to graze cattle. The integrity of the vernal pool complexes in eastern 
Merced is threatened by the proposed UC Merced Campus and associated 
development. Succulent owl's-clover has been found in 296 vernal pools 
in the proposed campus and community area, although only 34 percent of 
the area was surveyed intensively (EIP Associates 1999). Construction 
of facilities to educate and serve twenty-five thousand UC students as 
well as faculty, staff, and their families within the vernal pool 
complexes in eastern Merced County, could have a major impact on the 
survival and recovery of succulent owl's-clover. However, the recent 
draft biological opinion for the UC Merced campus and community 
developed environmental parameters which should reduce impacts to 
vernal pool habitats. Indirect and cumulative impacts of the proposed 
1,673 ha (4,133 ac) campus and associated community may be minimized 
with the creation of a 2,036 ha (5,030 ac) preserve intended to protect 
sensitive vernal pool habitat, to be purchased with money donated by 
the Packard Foundation.
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery, as well as elevation contours in the 
eastern foothill region and sub-watershed boundaries. The Merced Unit 
is comprised of two subunits, Subunit A is located north of the Merced 
River, and south of Dry Creek. Subunit B is located south of the Merced 
River and north of Mariposa Creek Both subunits are located east of 
State Highway 99. Approximately 419 ha (1,048 ac) is owned by the DOD, 
3 ha (8 ac) by U.S. Bureau of Reclamation (BOR), 10 ha (26 ac) by 
California State Parks. TNC has 4,513 ha (11,283 ac) of easement lands 
within this unit. The remaining lands within this unit are privately 
owned. The Merced Unit overlaps with vernal pool tadpole shrimp Unit 
15, vernal pool fairy shrimp Unit 22, Conservancy fairy shrimp Unit 6, 
hairy Orcutt grass Unit 5, Hoover's spurge Unit 5, Greene's tuctoria 
Unit 7, San Joaquin Valley Orcutt grass Units 2 and 3, and Colusa grass 
Units 5 and 6. Other sensitive vernal pool species found within this 
unit include California linderiella, California tiger salamander, 
shining navarretia, dwarf downingia, and Bogg's Lake hedge-hyssop.

Unit 4, Madera Unit, Madera County (33,071 ha (81,717 ac))

    This unit is proposed as critical habitat for succulent owl's-
clover because it supports multiple occurrences of the species within 
hardpan vernal pools on soils of alluvial fans and terraces, including 
San Joaquin soils (CNDDB 2002). This unit is important for the survival 
of succulent owl's-clover because it represents large areas of 
contiguous habitat with relatively intact hydrology. These pools are 
typically found in vernal pool/swale complexes on mima mound 
topography. This unit contains vernal pools and other ephemeral 
features and associated watersheds that maintain suitable periods of 
pool inundation, water quality, and soil moisture for succulent owl's-
clover germination, growth, reproduction, and dispersal.
    Most of the area within this unit is on private land, although a 
large population of succulent owl's-clover occurs on property acquired 
by the California Department of Transportation for mitigation purposes 
(CNDDB 2001). The integrity of vernal pool complexes and their 
associated watersheds in the Madera Unit is threatened by agricultural 
conversion and urban encroachment.
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery, as well as elevation contours in the 
eastern foothill region and sub-watershed boundaries. Located entirely 
in Madera County, this unit contains vernal pool habitat extending from 
the Chowchilla River in the north to the San Joaquin River in the 
south. All vernal pools in this unit are located east of State Highway 
99. Land ownership within the unit includes 3 ha (8 ac) by BOR, 2 ha (5 
ac) by NPS, 47 ha (117 ac) by CDFG, and 9 ha (22 ac) by State Land 
Commission. The Madera Unit overlaps hairy Orcutt grass Units 6 and 7, 
Greene's tuctoria Unit 8, San Joaquin Valley Orcutt grass Units 4 and 5 
and vernal pool fairy shrimp Unit 24A. Other sensitive vernal pool 
species found within this unit include spiny-sepaled button-celery, 
California tiger salamander, western spadefoot toad and California 
linderiella.

Unit 5, Fresno Unit, Fresno County (11,888 ha (29,375 ac))

    This unit is proposed as critical habitat for succulent owl's-
clover because it contains occurrences of the species growing within 
vernal pools formed on Fallbrook, Ramona, San Joaquin, Vista, and 
Pollasky soil series

[[Page 59948]]

(CNDDB 2002). The diversity of vernal pool types found within the 
Fresno Unit contributes to the range of ecological conditions in which 
succulent owl's-clover occurs. This area represents the southern extent 
of the species range. This unit contains suitable habitat within annual 
grassland communities to enable the species to carry out its life-
cycle. Some habitat in this unit consists of typical ``bowl-like'' 
pools, whereas other areas are more similar to swales. Vernal pools 
within this unit have been destroyed by conversion to irrigated 
agriculture, as well as urban encroachment from the cities of Fresno 
and Clovis.
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery. Located in Fresno County, this unit 
contains vernal pool habitat extending from the San Joaquin River in 
the north to Shaw Avenue in the south. The western boundary of this 
unit lies east of Fresno and Clovis and the eastern boundary parallels 
the low elevation foothill region of the Sierra Nevada. Property 
ownership and protection within this unit includes CDFG (0.4 ha (1 ac)) 
and CDFG administered land (0.4 ha (1 ac)). The remainder of the 
property within this unit is privately owned. The Fresno Unit overlaps 
San Joaquin Valley Orcutt grass Unit 5 and vernal pool fairy shrimp 
Unit 24B. Other sensitive vernal pool species found within this unit 
include California linderiella, California tiger salamander, and 
western spadefoot toad.

Unit 6A and B, Table Mountain Unit, Fresno and Madera Counties, (1,723 
ha (4,258 ac))

    This area is proposed as critical habitat for succulent owl's-
clover because it supports occurrences of the species within Northern 
Basalt Flow vernal pools (CNDDB 2002). This is the only area where 
succulent owl's-clover is found on this vernal pool type. Northern 
Basalt Flow pool complexes, such as Table Mountain, are extremely rare, 
occurring only on ancient terraces and hilltops. Basalt tables are 
perched on narrow, sinuous basalt mesas above the surrounding low-lying 
terrain. They typically contain small, irregularly clustered pools with 
``flashy hydrology'' (Keeler-Wolf et al. 1998). They are less common 
than hardpan and claypan pools that are typically found in this region, 
and occur in complexes that are less dense than habitat in units 
further north.
    Three occurrences of succulent owl's-clover within this unit are 
wholly or in part within designated reserves, which are on two 
``tabletop'' mountains near Millerton Lake. The Sierra Foothill 
Conservancy's Big Table Mountain Preserve includes one of these 
occurrences and a portion of another, which is shared with the BLM. The 
other is in the CDFG's Big Table Mountain Ecological Reserve. A fourth 
occurrence, which is on a nearby tabletop, is partially under the 
control of the BLM and partly in private ownership. A cooperative group 
consisting of the CDFG, California Department of Parks and Recreation, 
Sierra Foothill Conservancy, BLM and BOR has developed a management and 
monitoring plan for Big Table Mountain. Initial efforts of the plan 
will focus on grazing as a means to control non-native grasses while 
comparing population trends of threatened and endangered species in 
grazed and ungrazed portions of the tableland (Griggs in litt. 2000a). 
BLM owns approximately 149 ha (371 ac) and CDFG owns approximately 429 
ha (172 ac) of land within this unit. TNC has 256 ha (650 ac) of 
conservation easements within this unit. The BLM has attempted to 
protect the occurrence on the other tabletop mountain by erecting 
fencing to prevent trespass by cattle (Franklin in litt. 1993).
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery, as well as elevation contours in the 
eastern foothill region and sub-watershed boundaries. Unit 6 for 
succulent owl's-clover is comprised of two subunits. Both subunits are 
located east of Millerton Lake on basalt mesas above the San Joaquin 
River. Subunit 6B is located on Kennedy Table in Madera County, and 
Subunit 6A is directly south of this unit across the San Joaquin River 
on Table Mountain in Fresno County. The Table Mountain Rancheria is 
south of this unit. Unit 6 coincides with vernal pool fairy shrimp Unit 
25, vernal pool tadpole shrimp Unit 17, and San Joaquin Valley Orcutt 
grass units 6A and 6B. Other sensitive vernal pool species found within 
this unit include Bogg's lake hedge-hyssop and California linderiella.

Colusa Grass Criteria

    In proposing critical habitat units for Colusa grass, we evaluated 
the life history and current distribution of the species, the primary 
constituent elements, and the current threats to the species. This 
information allowed us to determine which areas are most likely to 
contribute to the conservation of Colusa grass.
    Currently, the CNDDB (2001) includes 59 occurrences of Colusa 
grass; 48 occurrences are presumed to be extant and 11 others are 
either known or presumed to be extirpated. The extant populations occur 
primarily in the foothills region of the San Joaquin Valley, where 80 
percent known occurrences are found northeast of the city of Merced in 
Merced County and east of Hickman in Stanislaus County. Of the 
remaining extant occurrences, four are in central Merced County, and 
two each occur in southeastern Yolo and central Solano counties (Stone 
et al. 1988, Keeler-Wolf et al. 1998, CNDDB 2001). This species has 
been extirpated from Colusa County (CNDDB 2001).
    Colusa grass declined primarily because pools in which it occurred 
were destroyed by conversion to irrigated agriculture, primarily to 
orchards and vineyards (Crampton 1976, Medeiros 1976, CNDDB 2002). 
Agricultural conversion continues to threaten Colusa grass. In eastern 
Stanislaus County agricultural conversion threatens the 16 occurrences 
(33 percent) there. Dry-land farming there is gradually being replaced 
by irrigated agriculture; the former apparently is compatible with the 
persistence of Colusa grass, but the latter is not (Crampton 1959, 
Crampton 1976).
    Other factors that extirpated populations of Colusa grass included 
surface disturbances and degradation of vernal pool hydrology. At least 
9, and possibly 11, occurrences have been extirpated as a result of 
these factors, although several others most likely were eliminated 
before being reported (Stone et al. 1988). Changes in natural 
hydrology, such as draining pools or creating reservoirs, could create 
unsuitable conditions for Colusa grass by decreasing or increasing 
inundation periods. The two Yolo County occurrences are threatened by 
herbicide run-off from adjacent agricultural operations (CNDDB 2002).
    Additional factors threaten the survival of Colusa grass, 
particularly the problem of small population size. Although populations 
may drop to only a few visible plants in certain years, seven 
populations consisted of fewer than 100 plants even at their peak 
(CNDDB 2002) and thus are likely to be small populations. Non-native 
plants and invasive native species could invade Colusa grass 
occurrences and may be particular problems in combination with other 
factors such as decreased inundation and inappropriate livestock 
grazing (Stone et al. 1988, Witham in litt. 2000a). Grasshopper 
foraging has been observed on Colusa

[[Page 59949]]

grass (Stone et al. 1988), but the extent of this threat is unknown.

Colusa Grass Unit Review

    We conducted a regional review across the range of Colusa grass to 
evaluate and select areas that are essential to the conservation of the 
species and that may require special management. Important factors we 
considered were the presence of the species and the presence of the 
primary constituent elements essential to the conservation of the 
species. A specific description of each area is outlined below.

Unit 1, Davis Communications Annex and Grasslands Area Unit, Yolo 
County (192 ha (474 ac))

    This unit is proposed as critical for Colusa grass because it 
contains one of six areas where the species is known to occur (CNDDB 
2002, Yolo County Parks 2001, EIP Associates 2001) within large vernal 
playa pools of the Pescadero soil series (Holland 1998, USDA 2001, Yolo 
County 1995).
    The unit boundary was drawn to include the vernal pool complex 
mapped by Holland (1998) and Yolo County Parks (2001) where Colusa 
grass is known to occur. This vernal pool complex maintains suitable 
periods of pool inundation, water quality, and soil moisture for Colusa 
grass germination, growth and reproduction, and dispersal, but not 
necessarily every year. Colusa grass in this unit is threatened by 
altered hydrology, contamination, competition with invasive plant 
species, and surface disturbances such as discing.
    This unit is located southeast of the City of Davis and south of 
the South Fork of Putah Creek. This unit's western boundary coincides 
with the Solano and Yolo county line. This unit also represents Unit 1 
for Solano grass, and is a portion of Unit 10 for vernal pool tadpole 
shrimp. The unit contains land owned by Yolo County. Approximately 128 
ha (322 ac) is owned by the DOD.

Unit 2, Jepson Prairie Unit, Solano County (7,153 ha (17,675 ac))

    This unit is proposed as critical for Colusa grass because it 
supports the species (CNDDB 2002) within large, alkaline, playa type 
vernal pools (Holland 1998, USDA 2001, Solano County 2000, Solano 
County Farmlands and Open Space 2000). These pools occur on Pescadero 
and Antioch-San Ysidro soil series, and contribute to the diversity of 
vernal pool types where the species is found. The unit boundary was 
drawn to include the vernal pool complex where Colusa grass is known to 
occur. The pools, swales, and adjacent uplands that comprise this 
complex are essential to maintain the necessary timing and length of 
pool inundation for Colusa grass germination, growth, pollination, seed 
production, and dispersal. This unit includes one of the largest 
contiguous areas of habitat remaining for the species. The relatively 
undisturbed, hydrologically intact condition of the vernal pool 
habitats within this unit increase the likelihood that it will continue 
to support natural vernal pool ecosystem processes and maintain 
suitable habitat conditions for Colusa grass.
    This unit includes the Jepson Prairie Preserve (623 ha (1,558 ac), 
jointly managed by the Solano County Farmlands and Open Space and the 
UC Reserve System. Jepson Prairie contains large playa-like vernal 
pools which may be over several acres in size, including the 32 ha (80 
ac) Olcott Lake. These larger pools often occur in complexes with 
smaller pools and hogwallow depressions. Jepson Prairie has long been 
recognized as an outstanding example of vernal pool ecosystems. In 
1987, the NPS named Jepson Prairie a National Natural Landmark, a 
designation given to well preserved sites that illustrate a particular 
type of natural feature and provide high quality habitat for threatened 
or endangered species. Jepson Prairie is the target of ongoing 
conservation planning and active management. As part of the UC Reserve 
System, this area also provides critical research opportunities for 
scientists to study vernal pool species, including Colusa grass. The 
unit also contains lands totaling 248 ha (620 ac) owned and 
approximately 64 ha (161 ac) administered by CDFG. Additional lands are 
owned by DOD (93 ha (233 ac)), and the State Land Commission (7 ha (17 
ac)), with another 436 ha (1,090 ac) of private land protected under 
WRP easements or agreements. Within the greater Jepson Prairie 
grassland area, existing vernal pools are threatened by agricultural 
conversion, landfill expansion, power plant construction, and utility 
maintenance.
    This unit is situated east of the City of Fairfield, south of the 
City of Dixon, and north of the Montezuma Hills and the confluence of 
the Sacramento and San Joaquin rivers. This unit is also described as 
Unit 2 for Solano grass. This unit is encompassed by Unit 3 for 
Conservancy fairy shrimp, Unit 11 for vernal pool tadpole shrimp, and 
Unit 16 for vernal pool fairy shrimp. This unit also supports a diverse 
community of plants and animals, including the only known occurrence of 
delta green ground beetle, and occurrences of California tiger 
salamander, alkali milk-vetch, Bogg's Lake hedge-hyssop, legenere, 
California linderiella, and midvalley fairy shrimp.

Unit 3, Farmington Unit, Stanislaus County (16,475 ha (40,709 ac)

    This unit was identified as critical for Colusa grass because the 
species is found (CNDDB 2002) within vernal pools on high terrace 
landforms and Redding-Pentz-Peters soil complexes (USDA 2001). The 
impermeable layers underlying these occupied vernal pools are generally 
iron-silica cemented hardpan. The Farmington Unit contains pools, 
swales, and other ephemeral wetlands and depressions of appropriate 
sizes and depths and the adjacent upland margins of these depressions 
that sustain Colusa grass germination, growth, and reproduction. 
Habitat in this unit includes deeper pools that are most likely to 
provide the long inundation period required for germination of Colusa 
grass (EIP Associates 1999). This unit is isolated from the other 
Colusa grass units to the north by over 80 km (50 mi).
    The Farmington unit is located in northeast Stanislaus County. It 
is hydrologically separated from units to the south by the Stanislaus 
River. The eastern boundary generally parallels the Calaveras County 
Line. Woodward Reservoir and the town of Oakdale are all located 
outside and to the west of the unit. The unit is generally south of 
State Highway 4 and north of State Highway 108. The unit boundary was 
drawn to include these species occurrences and the vernal pool 
complexes in which they occur as mapped by Holland (1998) and as 
visible on SPOT imagery. Lands within this unit are privately owned.

Unit 4, Waterford Unit, Stanislaus and Tuolumne Counties (35,134 ha 
(86,814 ac))

    The Waterford Unit was identified as critical habitat for Colusa 
grass because it contains large occurrences of Colusa grass. 
Approximately one-fifth of all extant occurrences are found within this 
unit (CNDDB 2002). These occurrences are found within vernal pools 
formed on alluvial terraces and associated Whitney soils, among others. 
These pool types provide the necessary timing and length of inundation 
for Colusa grass to germinate, mature, and set seed. The Waterford Unit 
contains very large vernal pool complexes that will likely continue to 
support vernal pool ecosystem processes important to the conservation 
of Colusa grass. This unit contains vernal pools, swales, and other 
ephemeral wetlands and depressions of appropriate sizes and depths and 
the

[[Page 59950]]

adjacent upland margins of these depressions that sustain Colusa grass 
germination, growth and reproduction, and that typically become 
inundated during winter rains, including, but not limited to vernal 
pools formed on acidic soils of alluvial fans and stream terraces along 
the eastern margin of the San Joaquin Valley and into the adjacent 
foothills.
    Agricultural conversion has resulted in the extirpation of at least 
two documented Colusa grass occurrences in this unit. Although Colusa 
grass has the ability to persist with dry-land farming, dry-land 
farming is gradually being replaced by irrigated agriculture throughout 
this unit.
    The Waterford Unit is bordered by the Stanislaus River to the north 
and the Tuolumne River to the south. The City of La Grange is located 
southeast of this unit. County Road J9 runs west of the unit, and 
Oakdale is located outside of the northwest corner. The eastern 
boundary extends into the low elevation foothills of the Sierra Nevada. 
Vernal pools in the Waterford Unit are mainly located in eastern 
Stanislaus County, but overlap into southwestern Tuolumne county. 
Approximately 0.8 ha (2 ac) of this unit are lands administered by the 
CDFG. The unit boundary was drawn to include species occurrences and 
the vernal pool complexes in which they occur as mapped by Holland 
(1998) and as visible on SPOT imagery. Watershed boundaries were also 
used in the determination. This unit coincides with Hoover's spurge 
Unit 4, San Joaquin Valley Orcutt grass Unit 1, and hairy Orcutt grass 
Unit 4. It overlaps with Greene's tuctoria Unit 5, succulent owl's-
clover Unit 2, and vernal pool tadpole shrimp Unit 13.

Unit 5, Turlock Unit, Stanislaus and Merced Counties (19,850 ha (49,049 
ac))

    This unit is proposed as critical habitat for Colusa grass because 
it supports large, playa vernal pools where the species is found (CNDDB 
2002, Holland 1998). The well-known Hickman pools in Stanislaus County 
are located within this unit. These unusual pools provide a unique 
habitat for Colusa grass, as well as a number of other vernal pool 
species. Not only does the Hickman pool complex contain one of the 
largest vernal lakes in California, occupying more than 121 ha (300 
ac), but it also exhibits tremendous biodiversity, including one of the 
largest concentrations of imperiled amphibians (Medeiros 2000). Other 
habitat in this unit contains the primary constituent elements 
essential to the conservation of Colusa grass, including soil type and 
deeper pools that are more likely to provide the long inundation period 
required for germination.
    The watershed containing the Hickman Colusa grass occurrences has 
been breached by hundreds of acres of orchards that have been planted 
upstream. While most of the watershed has been managed over the years 
in a trust of the Fred Robinson family, the integrity of the vernal 
pool ecosystem is threatened by agricultural development and potential 
biocide pollution (Medeiros 2000). Much of the irrigated farmland 
habitat adjacent to the western edge of this unit was historically 
vernal wetlands. Intensive agriculture poses the largest threat to 
Colusa grass habitat in the Turlock Unit.
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery. The Turlock Unit is bordered by the 
Tuolumne River to the north and the Merced River to the south. The unit 
lies between the towns of La Grange and Snelling. County Road J9 runs 
west of the unit and the eastern edge is located in the low elevation 
foothills of the Sierra Nevada. Vernal pools in the Turlock Unit are 
located in Stanislaus and Merced counties. Approximately 61 ha (24 ac) 
of lands within this unit are owned by the California State Parks. This 
unit coincides with hairy Orcutt grass Unit 5. Portions of this unit 
overlap with Hoover's spurge Unit 5, vernal pool fairy shrimp Unit 21, 
and succulent owl's-clover Unit 3A.

Unit 6, Merced Unit, Merced and Mariposa Counties (45,641 ha (112,779 
ac))

    This unit is proposed as critical for Colusa grass because it 
contains over 40 percent of all known Colusa grass occurrences (CNDDB 
2002). This unit also contains a diversity of habitats for Colusa 
grass, including the only locations where this species is known to 
occur on Keyes-Pentz, Redding, and Keyes soils (USDA 2001). Although 
many populations of Colusa grass have been extirpated in the past two 
decades, populations in the Merced Unit are among the most robust 
remaining (Holland 2000). The area within this unit encompasses the 
largest block of pristine, high density vernal pool grasslands 
remaining in California (Vollmar 1999). It contains habitat for three 
listed branchiopods, six listed plants, and a number of rare species.
    The majority of the land in this unit is privately owned and is 
used to graze cattle. TNC is conserving three occurrences of Colusa 
grass through a conservation easement on the Flying M Ranch located 
northeast of the City of Merced. The integrity of the vernal pool 
complexes in eastern Merced is seriously threatened by irrigated 
agriculture, upland housing development, and the proposed UC Merced 
Campus and associated development. Construction of facilities to 
educate and serve 25,000 UC students as well as faculty, staff, and 
their families within the vernal pool complexes in eastern Merced 
County, could have a major impact on these vernal pools. However, the 
recent draft biological opinion for the UC Merced campus and community 
developed environmental parameters which should reduce impacts to 
vernal pool habitats. Indirect and cumulative impacts of the proposed 
1,673 ha (4,133 ac) campus and associated community may be minimized 
with the creation of a 2,036 ha (5,030 ac) preserve intended to protect 
sensitive vernal pool habitat, to be purchased with money donated by 
the Packard Foundation.
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery. A majority of the vernal pool habitat 
in the Merced Unit is in Merced County, although the eastern edge of 
the unit overlaps into Mariposa County in the low elevation foothills 
of the Sierra Nevada. The northern boundary parallels the Merced River, 
and Bear Creek serves as the southern border. The entire unit is 
located east of Highway 99. Approximately 419 ha (1,047 ac) of lands 
within this unit are owned by the USAF, 3 ha (8 ac) by BLM, and 10 ha 
(26 ac) by the California State Parks. The Merced Unit coincides with 
San Joaquin Valley Orcutt grass Unit 2, Conservancy fairy shrimp Unit 
6, vernal pool fairy shrimp Unit 22, and Hoover's spurge Unit 6. It 
overlaps with vernal pool tadpole shrimp Unit 15, Greene's tuctoria 
Unit 6, and succulent owl's-clover Unit 3B.

Unit 7A and B, Grassland Ecological Unit, Madera, Merced and Stanislaus 
Counties (8,163 ha (20,170 ac))

    This unit is proposed as critical habitat for Colusa grass because 
it contains vernal pools that support numerous occurrences of the 
species, including the only location where Colusa grass is found on 
clay or silty clay loam soils in the Landlow and Lewis series (Silveira 
in litt. 2000). The unit boundary was drawn to include these pool 
types, swales and associated uplands that comprise the vernal pool 
complexes mapped by Holland (1998)

[[Page 59951]]

where Colusa grass is known to occur. These vernal pool complexes 
maintain suitable periods of pool inundation, water quality, and soil 
moisture for Colusa grass germination, growth and reproduction, and 
dispersal, but not necessarily every year (CNDDB 2001). Remaining 
vernal pool complexes in this unit, particularly in the eastern 
subunit, have been fragmented by conversion to agriculture. These areas 
were historically interconnected vernal pool complexes, and current 
efforts are underway to restore wetland habitats in this area.
    The Grassland Ecological Unit includes Arena Plains and the Merced 
National Wildlife Refuges. We own and administer approximately 1,406 ha 
(3,514 ac) within this unit. Our personnel have been monitoring Colusa 
grass occurrences on National Wildlife Refuge lands within this unit 
annually since 1993. This Arena Plains and Merced NWR area contains the 
majority of vernal pool habitats remaining in the San Joaquin Valley 
and is the only location where Colusa grass occurs on the San Joaquin 
Valley floor. Threats to the vernal pools in this unit include 
agricultural conversion, changes in hydrology, invasion by aggressive 
plants, and inappropriate livestock grazing regimes.
    The unit lies north of the City of Los Banos, southwest of the City 
of Merced, and is bisected by the San Joaquin River. This unit overlaps 
Unit 23 for vernal pool fairy shrimp and Unit 16 for vernal pool 
tadpole shrimp. The western half of this unit also represents Unit 6 
for Hoover's spurge, and portions of Unit 7 for Conservancy fairy 
shrimp. In addition to the species mentioned above, vernal pool 
smallscale, alkali milk-vetch, western spadefoot toad, and California 
linderiella are present in this unit

Greene's Tuctoria

    In proposing critical habitat units for Greene's tuctoria, we 
evaluated the life history and current distribution of the species, the 
primary constituent elements, and the current threats to the species. 
This information allowed us to determine which areas are most likely to 
contribute to the conservation of this species and to delineate units 
so that threats to this species might be minimized.
    Since Greene's tuctoria was first described, 19 of the 39 known 
occurrences (50 percent of all occurrences) have been extirpated. The 
other 20 occurrences are presumed to be extant, although 6 of those 
have not been verified for more than a decade (Alexander and Schlising 
1997, CNDDB 2001). Greene's tuctoria is currently known from the Vina 
Plains area of Tehama and Butte counties, from portions of eastern 
Merced County, and from isolated occurrences in Glenn and Shasta 
counties (CNDDB 2001). The species is considered possibly extirpated 
from Fresno, Madera, San Joaquin, Stanislaus, and Tulare counties 
(Stone et al. 1988, Skinner and Pavlik 1994, CNDDB 2001). The areas 
that continue to support robust occurrences of the species include the 
Vina Plains area of Tehama and Butte counties, and an area in eastern 
Merced County. All other occurrences are considered declining and may 
require special management actions to ensure their long-term 
conservation.
    One of the primary causes of extirpation for Greene's tuctoria has 
been conversion to irrigated agriculture; 11 of 19 (57.9 percent) 
extirpated occurrences were due at least in part to agricultural 
conversions. Stanislaus and Fresno counties experienced the greatest 
loss to agricultural conversion, with four and three such extirpations, 
respectively. Excessive livestock grazing was the sole or partial cause 
of extirpation for six populations (31.6 percent) (Stone et al. 1988, 
CNDDB 2002).
    Greene's tuctoria is less tolerant of livestock grazing and 
competition than most of the other Orcuttieae, probably because it 
occurs in portions of pools that dry early in the spring. Anecdotal 
evidence of its lower tolerance to grazing is that Greene's tuctoria 
has disappeared from one grazed site where Hoover's spurge still occurs 
and from another site where Colusa grass remains (CNDDB 2002). Fifteen 
of the 20 remaining populations are subject to cattle grazing and the 
associated trampling, and at least 4 of those are declining (Stone et 
al. 1988, CNDDB 2001). Four other occurrences on the Vina Plains 
Preserve had been declining (Stone et al. 1988, CNDDB 2001), but 
improved after grazing was discontinued. Invasion from weedy plants, 
such as cocklebur (Xanthium sp.) and other non-native species, 
apparently is reducing population vigor at six localities in the 
Sacramento and San Joaquin valleys (Stone et al. 1988, Alexander in 
litt. 1998, CNDDB 2001). Agricultural conversion remains a threat to 
the Merced County populations, which are the only ones confirmed to be 
remaining in the San Joaquin Valley. Grasshoppers have been documented 
to consume entire populations of Greene's tuctoria before they set seed 
(Griggs 1980, Griggs and Jain 1983, Stone et al. 1988).
    Finally, small populations of Greene's tuctoria (fewer than 100 
plants) may limit persistence of several occurrences. One population in 
Merced County consisted of only a single plant in 1987, and one in 
Butte County contained 75 plants (Stone et al. 1988, CNDDB 2001). The 
Shasta County population also may have declined to the point where it 
is more vulnerable to extirpation by random events, such as fire, or by 
other threats as previously discussed; the Shasta County population 
consisted of 2,500 plants in 1993 and 1994, but declined to 120 in 1996 
and 35 in 1998 despite favorable hydrological conditions. However, 
additional investigation of all four populations is necessary to 
determine whether or not larger soil seed banks exist.

Greene's Tuctoria Unit Review

    We conducted a regional review across the range of Greene's 
tuctoria to evaluate and select areas that are essential to the 
conservation of the species and that may require special management. 
Important factors we considered were the known presence of the species 
and the presence of the primary constituent elements essential to the 
conservation of the species. A specific description of each area is 
outlined below.

Unit 1, Modoc Plateau Unit, Lassen, and Shasta Counties (973 ha (2,403 
ac))

    This unit is proposed as critical habitat for Greene's tuctoria 
because it contains the species within Northern Basalt Flow vernal 
pools (CNDDB 2002) and the vernal pool habitat remains inundated for 
sufficient periods of time to allow Greene's tuctoria to complete its 
life cycle. These areas are not threatened by land conversion or 
development at this time due to their remote location, however, grazing 
activities may be contributing to the species decline in this area and 
may require special management actions, such as reduction or 
elimination of grazing, to prevent further decline and possible 
extirpation of the occurrence within this unit (CNDDB 2001).
    Greene's tuctoria within this unit are located within an area 
described as a large vernal pool in an open flat in an eastside pine 
forest. The occurrence is located at higher elevations and has the 
coldest climatic conditions of any other occurrences and represents the 
northern extent of the species range. This unit is over 110 km (68 mi) 
disjunct from occurrences further south. Isolated and peripheral 
populations such as this may be essential to the overall long-term 
conservation of the species (i.e., may be genetically different from 
other

[[Page 59952]]

populations in other parts of its range) (Lesica and Allendorf 1995).
    The boundaries of this unit were delineated by using SPOT imagery 
and elevation contours to include the open flat area associated with 
the vernal pool including the adjacent uplands that contribute to the 
filling and drying of the vernal pool where Greene's tuctoria occur, 
and maintain suitable periods of pool inundation, water quality, and 
soil moisture for Greene's tuctoria to germinate and reproduce. 
Approximately 892 ha (2,231 ac) of this unit is owned by the USFS. The 
remaining lands within this unit are privately owned.
    This unit for Greene's tuctoria occurs within the volcanic plateau 
of northeastern California. The unit is located in the area surrounding 
Murken Lake east of Hat Creek near Cinder Butte. Bidwell Road crosses 
through the southern boundary. This is the only unit where Greene's 
tuctoria occupies Northern Basalt Flow vernal pools. Maintaining this 
ecologically distinct unit is essential to the conservation of the 
species because it is the northern extent of its range, and is 
essential to maintain the diversity of habitats in which Greene's 
tuctoria is known to occur.

Unit 2, Vina Unit, Tehama and Butte Counties (11,673 ha (28,845 ac))

    This unit is proposed as critical habitat for Greene's tuctoria 
because it contains occurrences of the species within vernal pools 
(CNDDB 2002) and the vernal pool habitat remains inundated for 
sufficient periods of time to allow Greene's tuctoria to complete its 
life cycle. This unit is proposed as critical for Greene's tuctoria 
because it includes 60 percent of the occurrences that are thought to 
be extant (CNDDB 2001). Greene's tuctoria occurs within vernal pools 
found on Anita and Tuscan soil series within this unit. These pool 
types maintain the necessary timing and length of inundation for 
Greene's tuctoria germination, growth, and reproduction (CNDDB 2002). 
This unit represents one of only two areas throughout the species range 
where Greene's tuctoria occurrences are not considered to be declining 
(CNDDB 2001).
    The boundaries of this unit were delineated to include the 
interconnected pools, swales, and associated uplands mapped by Holland 
(1998) that contribute to the filling and drying of the vernal pools 
where the species occur, and maintain suitable periods of pool 
inundation, water quality, and soil moisture for Greene's tuctoria 
germination and reproduction.
    The majority of the lands included within this unit are privately 
owned. This unit contains TNC's 1,862 ha (4,600 ac) Vina Plains 
preserve. The preserve contains over 300 species of plants, and diverse 
communities of aquatic invertebrates. Since the 1960's, the Vina Plains 
area has been the focus of a number of research projects, including 
long-term adaptive management and monitoring efforts evaluating of the 
effects of grazing and fire on vernal pool plants, including Greene's 
tuctoria (Griggs 2000). Much of the basic life history information 
known about Greene's tuctoria was collected at Vina Plains (e.g., Stone 
et al. 1988, Alexander and Schlising 1997). The results of this 
research have provided crucial information to guide management and 
monitoring of vernal pool ecosystems and to identify factors which 
influence population dynamics of a number of endangered species, 
including Greene's tuctoria. The Vina Plains is open to the public and 
provides excellent outreach and educational opportunities. In addition 
to TNC, the importance of vernal pool habitats in this area has been 
recognized by CDFG, the Service, the EPA, the CNPS, the NRCS's WRP, and 
by researchers at the CSU at Chico, who have all supported research and 
conservation efforts for Greene's tuctoria and other vernal pool 
species within this unit. Urban development north of Chico and the 
conversion of grazed lands to more intensive agricultural uses threaten 
vernal pool habitat within this unit. Property ownership and protection 
within this unit includes CDFG (0.4 ha (1 ac)), CDFG administration 
(0.4 ha (1 ac)), TNC (2,295 ha (5,738 ac)), TNC easements (4,661 ha 
(11,653)), and WRP easements and agreements (57 ha, 142 ac)).
    This unit for Greene's tuctoria occupies the area south of Toomes 
Creek, and north of Pine Creek and the Cana Highway. State Route 99 
bisects this unit and the western boundary generally parallels the 
Southern Pacific Railway line. This unit is within Unit 7 for vernal 
pool fairy shrimp and Unit 3 for vernal pool tadpole shrimp, and 
encompasses part of Unit 1 for Conservancy fairy shrimp and Unit 1 for 
Butte County meadowfoam. The unit coincides with Unit 1 for hairy 
Orcutt grass, and Unit 4 for slender Orcutt grass and portions of Unit 
1 for Hoover's spurge. Additional sensitive vernal pool species 
occurring in this unit include California linderiella and Bogg's Lake 
hedge-hyssop.

Unit 3, Butte Unit, Butte County (979 ha (2,418 ac))

    This unit is proposed as critical habitat for Greene's tuctoria 
because it supports the species within large vernal pools on Tuscan 
soils (EPA 1994, Holland 1998, CNDDB 2002). These pools have the 
necessary timing and length of inundation for Greene's tuctoria 
germination, growth, and reproduction that typically become inundated 
during winter rains, but are dry during the summer. This occurrence may 
be threatened by overgrazing, and is described as ``possibly 
declining'' by CNDDB (2002).
    Vernal pool habitats within this area have become greatly 
fragmented and isolated from other habitats in the region. This area is 
one of only four areas occupied by Greene's tuctoria in the Sacramento 
Valley. This area is important to maintain the geographical 
distribution of Greene's tuctoria through out the areas where it 
occurs. The boundaries of this unit were delineated to include the 
interconnected pools, swales, and associated uplands mapped by Holland 
(1998) that contribute to the filling and drying of the vernal pools 
where the species occur, and maintain suitable periods of pool 
inundation, water quality, and soil moisture for Greene's tuctoria 
germination and reproduction.
    This unit for Greene's tuctoria occupies the area north of the 
intersection of State Route 99 and Route 149 in Butte County. The 
eastern boundary extends up the watershed of Clear Creek and the 
western boundary extends south paralleling State Route 99 to Little Dry 
Creek. This unit is within Unit 9 for vernal pool fairy shrimp and Unit 
4 for vernal pool tadpole shrimp, and coincides with Unit 2 for hairy 
Orcutt grass and Unit 2 for Hoover's spurge. All the property within 
this unit is privately owned.

Unit 4, Richvale Unit, Butte County (299 ha (738 ac))

    This unit is proposed as critical habitat for Greene's tuctoria 
because it contains occurrences of the species within vernal pools 
found on Rocklin and San Joaquin soils (CNDDB 2002) and the vernal pool 
habitat remains inundated for sufficient periods of time to allow 
Greene's tuctoria to complete its life cycle. This is the only area 
where Greene's tuctoria is found in vernal pools formed on these soil 
types.
    The boundaries of this unit were delineated to include the 
interconnected pools, swales, and associated uplands mapped by Holland 
(1998) that contribute to the filling and drying of

[[Page 59953]]

the vernal pools where the species occur, and maintain suitable periods 
of pool inundation, water quality, and soil moisture for Greene's 
tuctoria germination and reproduction.
    Vernal pool habitats within this area have become greatly 
fragmented and isolated from other habitats. This unit is over 200 km 
(120 mi) from the nearest Greene's tuctoria occurrences to the south. 
This occurrence of Greene's tuctoria helps to maintain the species 
range in the Sacramento Valley. This unit for Greene's tuctoria 
occupies the area west of the Thermalito Afterbay near the Richvale 
Highway and directly west of the Oroville Wildlife Area managed by CDFG 
(4 ha (9ac)). The remaining property within this unit is privately 
owned.

Unit 5, Sacramento National Wildlife Refuge Unit, Glenn and Colusa 
Counties (5,718 ha (14,129 ac))

    This unit is proposed as critical for Greene's tuctoria because it 
contains occurrences of the species within vernal pools that provide 
the necessary timing and length of inundation essential to the 
conservation of Greene's tuctoria, including alkaline vernal pools on 
Willows soils (Silveira 2000). Greene's tuctoria has been declining 
within this unit and we have taken management actions to prevent 
extirpation of the species from the refuge lands (Silveira 2000).
    This area is one of only four areas occupied by Greene's tuctoria 
in the Sacramento Valley. This occurrence is important to maintain the 
geographical distribution of Greene's tuctoria into the unique alkali 
flat habitats of the Colusa Basin. The boundaries of this unit were 
delineated to include the interconnected pools, swales, and associated 
uplands mapped by Holland (1998) that contribute to the filling and 
drying of the vernal pools where the species occur, and maintain 
suitable periods of pool inundation, water quality, and soil moisture 
for Greene's tuctoria germination and reproduction.
    This unit occurs predominantly on the Sacramento National Wildlife 
Refuge (5,126 ha (12,816 ac)). It is the only known location where 
Greene's tuctoria occurs on public land. It occurs east of Interstate 5 
to the Colusa Trough from Riz Road on the north and Delevan Road on the 
south. Other rare vernal pool species found in the unit include pappose 
spikeweed, Fremont's goldfields, alkali goldfields, Scribe's popcorn 
flower, Hoover's downingia, folded downingia, Heckard's peppergrass, 
heartscale, brittlescale, San Joaquin spearscale, Ferris' milk-vetch, 
spike-primrose, sessile mousetail, and palmate-bracted bird's beak. 
This unit is also part of vernal pool fairy shrimp Unit 10, and vernal 
pool tadpole shrimp Unit 5, and coincides with Unit 2 for Conservancy 
fairy shrimp, Unit 3 for Hairy Orcutt grass, and Unit 3 for Hoover's 
spurge.

Unit 6, Waterford Unit, Stanislaus and Tuolumne Counties (36,414 ha 
(89,978 ac))

    This unit is proposed as critical habitat for Greene's tuctoria 
because it supports occurrences of the species within vernal pools and 
swales that maintain the necessary primary constituent elements 
essential for its conservation, including the only vernal pools where 
Greene's tuctoria is known to occur on slightly alkaline soils of the 
Meikle and Paulsell series (CNDDB 2002, Holland 1998, USDA 2001). This 
unit contains numerous pools with occurrences and associated watersheds 
that contribute to the filling and drying of the vernal pool or 
ephemeral wetland, and that maintain suitable periods of pool 
inundation, water quality, and soil moisture for the germination, 
growth, reproduction, and dispersal of Greene's tuctoria.
    Agricultural conversion presents the greatest threat to habitat for 
Greene's tuctoria in this unit, and several occurrences within this 
unit have been extirpated or have severely declined as a result of 
agricultural conversion and intensive grazing (CNDDB 2002). This unit 
is over 200 km (120 mi) from the nearest Greene's tuctoria occurrences 
to the north. All occurrences in this unit are on private lands.
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery, as well as elevation contours in the 
eastern foothill region and sub-watershed boundaries. The Waterford 
Unit is bordered by the Stanislaus River to the north and the Tuolumne 
River to the south. The City of La Grange is located southeast of the 
unit. County Road J9 runs west of the unit, and the Oakdale Airport is 
located outside of the northwest corner. The eastern boundary extends 
into the low elevation foothills of the Sierra Nevada. Vernal pools in 
the Waterford Unit are located mainly in eastern Stanislaus County, but 
overlap into southwestern Tuolumne County. This unit overlaps with 
vernal pool tadpole shrimp Unit 13, San Joaquin Valley Orcutt grass 
Unit 1, hairy Orcutt grass Unit 4, Colusa grass Unit 5, Hoover's spurge 
Unit 4, and succulent owl's-clover Unit 2. Other sensitive vernal pool 
species found within this unit include California tiger salamander, 
western spadefoot toad, dwarf downingia, and California linderiella. 
Approximately 0.8 ha (2 ac) of this unit is administered by the CDFG. 
The remaining lands within this unit are privately owned.

Unit 7, Merced Unit, Merced, Madera, and Mariposa Counties (73,707 ha 
(182,127 ac))

    This unit is proposed as critical for Greene's tuctoria because it 
contains numerous occurrences of the species within large, 
hydrologically intact vernal pool grassland areas (Holland 1998, 
Vollmar 1999), including pools Northern Hardpan vernal pools on 
Redding, Raynor, and Bear Creek soils (USDA 2001, EIP 1999). Over 30 
percent of the extant occurrences of Greene's tuctoria are in the 
Merced Unit (CNDDB 2001). This unit contains the primary constituent 
elements necessary for conservation of the species including 
germination, growth, reproduction, and dispersal. This unit represents 
one of only two areas throughout the species range where Greene's 
tuctoria occurrences are not considered to be declining (CNDDB 2001).
    Agricultural conversion presents a great threat to habitat for 
Greene's tuctoria, particularly in areas along the western edge of this 
unit on the valley floor where irrigated agriculture has encroached on 
lands adjacent to occupied vernal pool complexes. The proposed UC 
Merced Campus and associated development will also have a significant 
impact on the long-term sustainability of vernal pool complexes. Other 
significant threats to Greene's tuctoria include urban encroachment and 
competition with non-native plants.
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery. A majority of the vernal pool habitat 
in the Merced Unit is in Merced County. The eastern edge of the unit 
overlaps into Mariposa County and in the south it extends to the 
Chowchilla River in Madera County. The northern boundary parallels the 
Merced River. The entire unit is located east of Highway 99. The Merced 
Unit coincides with vernal pool tadpole shrimp Unit 15 and vernal pool 
fairy shrimp Unit 22. It also encompasses hairy Orcutt grass Unit 6, 
succulent owl's-clover units 3B and 4, San Joaquin Valley Orcutt grass 
units 2 and 3, Colusa grass Unit 7, and Conservancy fairy shrimp Unit 
6. Other sensitive vernal pool species found within this unit include 
the California tiger salamander, shining navarretia, dwarf downingia, 
Bogg's Lake hedge-hyssop, western

[[Page 59954]]

spadefoot toad, and California linderiella. Approximately 419 ha (1,048 
ac) is owned by the DOD, 3 ha (4 ac) by BLM, 10 ha (26 ac) by 
California State Parks. TNC has 4,513 ha (11,283 ac) of easement lands 
within this unit. The remaining lands within this unit are privately 
owned.

Unit 8, Madera Unit, Madera County (13,222 ha (32,670 ac))

    This unit is proposed as critical habitat for Greene's tuctoria 
because the area supports occurrences of the species (CNDDB 2002). This 
occurrence represents the southern extent of the species currently 
known range. All other historical or previously documented occurrences 
to the south in Fresno and Tulare counties are considered extirpated 
(CNDDB 2002). Although this site is considered possibly extirpated, it 
is proposed as critical habitat until a determination of the current 
status of the occurrence can be made. Greene's tuctoria has a highly 
persistent soil seed bank, and it is likely that individuals exist in 
the soil as seeds even if adult plants have not been observed at the 
site in recent times. This unit contains areas that support vernal 
pools, swales, or other ephemeral ponds and depressions and their 
associated uplands. There are numerous wetland features that contain 
suitable inundation periods for Greene's tuctoria to germinate, grow, 
and reproduce. Vernal pools and their associated biota, particularly on 
the western edge of this unit closer to the valley floor, are 
progressively being degraded and replaced by irrigated agriculture and 
invasive plant species.
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery. Located in Madera County, this unit 
contains vernal pool habitat extending from the Chowchilla River in the 
north to the Fresno River in the south. All vernal pools in this unit 
are located east of State Highway 99 and extend into the low elevation 
foothill region of the Sierra Nevada. The town of Madera borders the 
unit on its southwest edge, Hensley Lake is east of the unit, and 
Eastman Lake is northeast of the unit. The Madera Unit overlaps with 
succulent owl's-clover Unit 4, San Joaquin Valley Orcutt grass units 3 
and 4, and hairy Orcutt grass Unit 6, and vernal pool tadpole shrimp 
Unit 15. Other sensitive vernal pool species found within this unit 
include California tiger salamander and California linderiella. All the 
lands within this unit are privately owned.

Hairy Orcutt Grass

    In proposing critical habitat units for hairy Orcutt grass, we 
evaluated the life history and current distribution of the species, the 
primary constituent elements, and the current threats to the species. 
This information allowed us to determine which areas are likely to 
contribute to the conservation of hairy Orcutt grass.
    Of the 38 hairy Orcutt grass element occurrences listed by the 
CNDDB (2001), not counting the misidentified population of San Joaquin 
Valley Orcutt grass, 24 are presumed to be extant. Nineteen of those 
occurrences have been confirmed as extant within the past decade (CNDDB 
2001). Currently, the main area of concentration for hairy Orcutt grass 
is the Vina Plains area in Tehama County. An isolated occurrence is 
found nearby in central Butte County. Several other occurrences are 
found in Madera County between the city of Madera and Millerton Lake. 
There are several occurrences in eastern Stanislaus County. All four 
extant occurrences in Glenn County occur on the Sacramento National 
Wildlife Refuge. Hairy Orcutt grass apparently has been extirpated from 
Merced County (Stone et al. 1988, Keeler-Wolf et al. 1998, CNDDB 2001).
    Historically, habitat loss was the primary factor responsible for 
the decline of hairy Orcutt grass. Of the 11 element occurrences 
considered by the CNDDB (2002) to be extirpated, 4 in Stanislaus County 
were converted to almond orchards or vineyards (Stone et al. 1988, 
CNDDB 2002). Most of the conversion occurred prior to 1976 (Crampton 
1959, Crampton 1976, Medeiros 1976, Reeder 1982). Two other occurrences 
in Madera County were lost by development for residences and orchards. 
The other five occurrences, which were in Madera, Merced, and 
Stanislaus counties, are listed as extirpated because the habitat was 
being used for irrigated pasture or dry farming or had been disced when 
they were last visited in 1986 and 1987 (Stone et al. 1988). However, 
continued field visits are advisable because another population 
reappeared several years after discing (CNDDB 2001).
    Hairy Orcutt grass no longer occurs in the Glenn County pool where 
it was found in 1937 because the area is now a permanent pond (J. 
Silveira pers. comm.). Inappropriate hydrology also may be responsible 
for the loss of one other occurrence at the Sacramento National 
Wildlife Refuge (Silveira in litt. 2000). The population consisted of 
20 plants when it was first discovered in 1993, but those plants died 
before setting seed due to flooding from a summer rainstorm, and none 
have been seen since that time (Silveira in litt. 2000). The population 
could reappear in future years if a substantial soil seed bank exists, 
and thus it is presumed to be extant.
    Habitat loss continues to pose a threat to the survival of hairy 
Orcutt grass. Agricultural and residential development are proceeding 
in the vicinity of the remaining Stanislaus and Madera county 
occurrences and may lead to the destruction of additional populations 
in the foreseeable future (Stone et al. 1988). Cattle grazing was an 
ongoing land use at 20 occurrences when they were last visited, 
including 6 where this species may already be extirpated (CNDDB 2002). 
Three occurrences are believed to have been eliminated by ``excessive'' 
livestock grazing, and seven others were damaged by summer grazing or 
overuse. However, ``moderate'' grazing in spring likely is compatible 
(Stone et al. 1988) and may be beneficial. Invasion of non-native 
plants is an increasing problem throughout the range of hairy Orcutt 
grass (Stone et al. 1988). Several researchers (Stone et al. 1988, 
Alexander and Schlising 1997) have suggested that cattle may have 
carried in seeds of non-native plants, and disturbance from trampling 
may have facilitated their establishment. Bindweed (Convolvulus sp.) 
has increased in frequency in the Vina Plains since 1984, and cocklebur 
is still present. Pools where hairy Orcutt grass grows had higher 
frequencies of these invasive species than did other pools on the Vina 
Plains Preserve in 1995 and altered hydrology may have contributed to 
the presence of invasive plants in the pools (Alexander and Schlising 
1997).

Hairy Orcutt Grass Unit Review

    We conducted a regional review across the range of hairy Orcutt 
grass to evaluate and select areas that are essential to the 
conservation of the species and that may require special management. 
Important factors we considered were the known presence of the species 
and the presence of the primary constituent elements essential to the 
conservation of the species. A specific description of each area is 
outlined below.

Unit 1, Vina Plains Unit, Tehama and Butte Counties (8,748 ha (21,617 
ac))

    This area is proposed as critical habitat for hairy Orcutt grass 
because it supports over 25 percent of all known occurrences of the 
species and contains large vernal pools occurring on Tuscan and Anita 
soils (USDA 2001, CNDDB

[[Page 59955]]

2002). The boundaries of this unit were delineated to include the 
interconnected pools, swales, and associated uplands mapped by Holland 
(1998) that contribute to the filling and drying of the vernal pools 
where the species occur, and maintain suitable periods of pool 
inundation, water quality, and soil moisture for hairy Orcutt grass 
germination and reproduction. This unit represents the northern extent 
of the species range, and is over 40 km (25 mi) from the nearest 
occurrence to the south. This area represents one of only two areas 
where large hairy Orcutt populations are protected, and where long-term 
monitoring of the species status has occurred.
    Hairy Orcutt grass may be threatened by invasive species within 
this unit (Alexander and Schlising 1997). In some areas special 
management actions have been taken to counteract the negative effects 
of invasive species on hairy Orcutt grass. For example, cocklebur, an 
aggressive native plant, has been removed by hand from some of the Vina 
Plains pools (Alexander and Schlising 1997), an effort that began in 
1991 using funds from the California Endangered Species Tax Check-Off 
Fund (CDFG 1991).
    The majority of the lands included within this unit are privately 
owned. This unit contains TNC's 1862-ha (4,600-ac) Vina Plains 
preserve. The preserve contains over 300 species of plants, and diverse 
communities of aquatic invertebrates. Since the 1960's, the Vina Plains 
area has been the focus of a number of research projects, including 
long-term adaptive management and monitoring efforts evaluating of the 
effects of grazing and fire on vernal pool plants, including hairy 
Orcutt grass (Griggs 2000). Much of the basic life history information 
known about hairy Orcutt grass was collected at Vina Plains (e.g., 
Stone et al. 1988, Alexander and Schlising 1997). The results of this 
research have provided crucial information to guide management and 
monitoring of vernal pool ecosystems and to identify factors which 
influence population dynamics of a number of endangered species, 
including hairy Orcutt grass.
    The Vina Plains is open to the public and provides excellent 
outreach and educational opportunities. In addition to TNC, the 
importance of vernal pool habitats in this area has been recognized by 
the CDFG, the Service, the EPA, the CNPS, the NRCS's WRP, and by 
researchers at the CSU at Chico, who have all supported research and 
conservation efforts for hairy Orcutt grass and other vernal pool 
species within this unit. Urban development north of Chico and the 
conversion of grazed lands to more intensive agricultural uses threaten 
vernal pool habitat within this unit.
    This unit for hairy Orcutt grass occupies the area south of Deer 
Creek and north of Pine Creek to near Cana Highway. State Route 99 
bisects this unit and the western boundary generally parallels the 
Southern Pacific Railway line. This unit is included within Unit 7 for 
vernal pool fairy shrimp, Unit 3 for vernal pool tadpole shrimp, Unit 1 
for Conservancy fairy shrimp, Unit 2 for Greene's tuctoria, Unit 1 for 
Hoover's spurge, and Unit 4 for slender Orcutt grass. Additional 
sensitive vernal pool species occurring in this unit include California 
linderiella and Bogg's Lake hedge-hyssop. Land ownership within this 
unit includes 2,264 ha (5,660 ac) by TNC and 57 ha (142 ac) of private 
land protected by conservation easement or agreement under the WRP. TNC 
has an additional 3,826 ha (9,564 ac) of conservation easements within 
this unit.

Unit 2, Butte Unit, Butte County, California (979 ha (2,418 ac))

    This unit is proposed as critical for hairy Orcutt grass because it 
supports the species within vernal pools on Tuscan soils (Holland 1998, 
USDA 1994, 1999, CNDDB 2002). These pool types remain inundated for 
sufficient periods of time to allow hairy Orcutt grass to complete its 
life cycle. This area and Unit 1 are the only locations where hairy 
Orcutt grass is found on the Tuscan soil types. This area comprises one 
of only three areas where this species occurs in the Sacramento Valley, 
and is important to maintain the species range and distribution. The 
northern occurrences of hairy Orcutt grass are isolated from 
occurrences in the southern part of the species range. This unit is 
over 40 km (25 mi) from the nearest units to the north and west, and 
over 225 km (140 mi) from the nearest unit to the south and is one of 
seven known occurrences of the species. This unit represents some of 
the last remaining lower elevation vernal pool habitats in Tehama and 
Butte counties.
    The boundaries of this unit were delineated to include the 
interconnected pools, swales, and associated uplands mapped by Holland 
(1998) and EPA (1994) that contribute to the filling and drying of the 
vernal pools where the species occur, and maintain suitable periods of 
pool inundation, water quality, and soil moisture for hairy Orcutt 
grass germination and reproduction.
    This unit for hairy Orcutt grass occupies the area north of the 
intersection of State Route 99 and Route 149 in Butte County. The 
eastern boundary extends up the watershed of Clear Creek and the 
western boundary extends south paralleling State Route 99 to Little Dry 
Creek. This unit is within Unit 9 for vernal pool fairy shrimp and Unit 
4 for vernal pool tadpole shrimp, and coincides with Unit 3 for 
Greene's tuctoria and Unit 2 for Hoover's spurge. All the lands within 
this unit are privately owned.

Unit 3, Sacramento Refuge Unit, Glenn and Colusa Counties (5,718 ha 
(14,129 ac))

    This unit is proposed as critical for hairy Orcutt grass because it 
contains multiple occurrences of the species within alkaline vernal 
pools on the Willows and Riz soil series (CNDDB 2002) and the vernal 
pool habitat remains inundated for sufficient periods of time to allow 
hairy Orcutt grass to complete its life cycle. This area is one of only 
three locations where hairy Orcutt grass is found in the Sacramento 
Valley. This area represents one of only two areas where large hairy 
Orcutt populations are protected, and where long-term monitoring of the 
species status has occurred.
    Habitat for hairy Orcutt grass is greatly fragmented in this 
portion of its range, and this unit is over 40 km (25 mi) from the 
nearest unit to the east, and over 225 km (140 mi) from the nearest 
unit to the south. Hairy Orcutt grass is known from only 7 general 
areas across its entire range, and each of these locations is essential 
to the conservation of this species.
    The boundaries of this unit were delineated to include the 
interconnected pools, swales, and associated uplands mapped by Holland 
(1998) that contribute to the filling and drying of the vernal pools 
where the species occur, and maintain suitable periods of pool 
inundation, water quality, and soil moisture for hairy Orcutt grass 
germination and reproduction.
    This unit for hairy Orcutt grass occupies the vernal pool habitat 
east of Interstate 5 to the Colusa Trough from Riz Road on the north 
and Delevan Road on the south. The area encompasses the Sacramento 
National Wildlife Refuge 5,126 ha (12,816 ac). This unit is also part 
of vernal pool fairy shrimp Unit 10, and vernal pool tadpole shrimp 
Unit 5, and coincides with Unit 2 for Conservancy fairy shrimp, Unit 5 
for Greene's tuctoria, and Unit 3 for Hoover's spurge. Other rare 
vernal pool species found in the unit include pappose spikeweed, 
Fremont's goldfields, alkali goldfields, Scribe's popcorn flower, 
Hoover's downingia, folded downingia, Heckard's

[[Page 59956]]

peppergrass, heartscale, brittlescale, San Joaquin spearscale, Ferris' 
milk-vetch, spike-primrose, sessile mousetail, and palmate-bracted 
bird's beak. The remaining land within this unit is privately owned.

Unit 4, Turlock Unit, Stanislaus and Merced Counties (25,318 ha (62,560 
ac))

    The Turlock Unit is proposed as critical habitat for hairy Orcutt 
grass because it contains occurrences of the species within large 
vernal pools on Whitney and Meikle soils that provide the necessary 
timing and length of inundation essential to the conservation of this 
species (CNDDB 2001, Holland 1998, USDA 2001). This unit contains the 
well known Hickman pools in Stanislaus County, and a high concentration 
of hairy Orcutt grass occurrences (CNDDB 2001). The Hickman pool 
complex contains one of the largest vernal lakes in California at more 
than 121 ha (300 ac) and represents a unique habitat for hairy Orcutt 
grass. This unit contains numerous vernal pools, swales, and other 
ephemeral wetlands and depressions of appropriate sizes and depths to 
sustain hairy Orcutt grass germination, growth, and reproduction.
    This unit contains large, intact vernal pool grasslands that help 
maintain the distribution of the species over its entire range. In 
vernal pool grasslands south of this unit, two hairy Orcutt grass 
occurrences are presumed extirpated as a result of agricultural 
conversion and intensive cattle grazing. Extant hairy Orcutt grass 
occurrences within this unit are threatened by altered hydrology, 
overgrazing, and competition with invasive species (CNDDB 2002). The 
watershed containing the Hickman vernal pools has been breached by 
hundreds of acres of orchards that have been planted upstream. The 
integrity of the vernal pool complexes in eastern Stanislaus and Merced 
counties is seriously threatened by irrigated agriculture, upland 
housing development, and the proposed UC Merced Campus and associated 
development.
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery. The Turlock Unit is bordered by the 
Tuolumne River to the north and the Merced River to the south. The unit 
lies between the towns of La Grange and Snelling. County Road J9 runs 
west of the unit and the eastern edge is located in the low elevation 
foothills of the Sierra Nevada. Vernal pools in the Turlock Unit are 
located in eastern Stanislaus and Merced counties. This unit coincides 
with Hoover's spurge Unit 5, Colusa grass Unit 7, Greene's tuctoria 
Unit 9 and succulent owl's-clover Unit 3A. It overlaps vernal pool 
fairy shrimp Unit 21. Land ownership within this unit includes BLM (7 
ha (17 ac)) and California State Parks (25 ha (61 ac)). The remaining 
land within this unit is privately owned.

Unit 5, Madera Unit, Madera County (9,085 ha (22,448 ac))

    This unit is proposed as critical habitat for hairy Orcutt grass 
because it contains occurrences of the species within vernal pools 
formed on Greenfield and Hanford soil series (Holland 1998, CNDDB 
2002). These soils support vernal pools, swales, and other ephemeral 
wetlands and depressions of appropriate sizes and depths to sustain 
germination, growth and reproduction of hairy Orcutt grass. To maintain 
the full range of ecological conditions in which this species occurs, 
conservation of hairy Orcutt grass populations and vernal pool habitat 
in the Madera Unit is important.
    The Madera Unit contains a California Department of Transportation 
mitigation site which protects a small occurrence of hairy Orcutt 
grass, and is the only conservation area for this species in the 
Southern Sierra Foothills. However, vernal pool habitat in and adjacent 
to this unit is progressively being eliminated and modified. An 
occurrence of hairy Orcutt grass approximately 11 km (7 mi) east of 
Madera has been extirpated due to residential development. The 
development of ranch-style homes, small horse pastures, orchards and 
new roads poses a serious threat to at least five other occurrences in 
or adjacent to this unit. However, hairy Orcutt grass has successfully 
been introduced into created vernal pools in this unit.
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery. Located in Madera County, this unit 
contains vernal pool habitat extending from the Chowchilla River in the 
north to the Fresno River in the south. The Fresno River separates this 
unit from the Cottonwood Creek Unit to the south. All vernal pools in 
this unit are located east of the Atchison, Topeka, and Santa Fe 
Railroad and extend into the low elevation foothill region of the 
Sierra Nevada. Berenda Creek bisects the unit. The town of Madera is 
located southwest of the unit, Hensley Lake is east of the unit, and 
Eastman Lake is northeast of the unit. The Madera Unit coincides with 
San Joaquin Valley Orcutt grass Unit 4, succulent owl's-clover Unit 4, 
and overlaps vernal pool fairy shrimp Unit 24A. Other sensitive vernal 
pool species found within this unit include California tiger salamander 
and California linderiella. All the land within this unit is privately 
owned.

Unit 6, Cottonwood Creek Unit, Madera County (15,824 ha (39,100 ac))

    This area is proposed as critical habitat for hairy Orcutt grass 
because it supports over 15 percent of the known occurrences of the 
species within Northern Claypan vernal pools formed on Cometa, 
Greenfield, Hanford soil series (CNDDB 2001, USDA 1994, Holland 1998). 
These pool types provide the necessary timing, length of inundation, 
water quality, and soil moisture for hairy Orcutt grass germination, 
growth and reproduction. The Cottonwood Creek Unit represents the 
southern extent of hairy Orcutt grass range. This unit contains large 
intact and contiguous vernal pool grassland areas that help maintain 
the distribution of the species through out its range.
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery, as well as elevation contours in the 
eastern foothill region and sub-watershed boundaries. Located in Madera 
County, this unit contains vernal pool habitat extending from the 
Fresno River in the north to the San Joaquin River in the south. The 
Fresno River separates this unit from the Madera Unit to the north. All 
vernal pools in this unit are located east of the Atchison, Topeka, and 
Santa Fe Railroad, extending east into the low elevation foothill 
region of the Sierra Nevada. Highway 41 bisects the eastern portion of 
the unit. The Cottonwood Creek Unit overlaps succulent owl's-clover 
Unit 4, San Joaquin Valley Orcutt grass Unit 4, and vernal pool fairy 
shrimp Unit 24A. Other sensitive vernal pool species found within this 
unit include California linderiella, spiny-sepaled button-celery, 
California tiger salamander, and western spadefoot toad. Approximately 
4 ha (10 ac) are owned by the CDFG.

Sacramento Orcutt Grass Criteria

    In proposing critical habitat units for Sacramento Orcutt grass we 
evaluated the life history and current distribution of the species, the 
primary constituent elements, and the current threats to the species. 
This information allowed us to determine which areas are likely to 
contribute to the conservation of Sacramento Orcutt grass.

[[Page 59957]]

    Sacramento Orcutt grass is found only in Sacramento County. The 
species was historically known from nine occurrences. However, one 
entire occurrence and a portion of another have been extirpated. Thus, 
eight of the nine occurrences are extant. Five occurrences, comprising 
more than 70 percent of the occupied habitat, are concentrated into a 
single area of approximately 6 sq km (2.3 sq mi) east of Mather Field. 
Two other occurrences are adjacent to each other--Phoenix Field 
Ecological Reserve and the introduced population at Phoenix Park. The 
eighth extant occurrence is near Rancho Seco Lake (Stone et al. 1988, 
Cochrane in litt. 1995a, Morey in litt. 1996, CNDDB 2002).
    Sacramento Orcutt grass was extirpated from its historic occurrence 
between Orangevale and Folsom by urban development. The species was 
extirpated from one pool near Grant Line Road by changes in hydrology--
pool depth was increased artificially to provide a longer-lasting water 
source for livestock, which created conditions unsuitable for 
persistence of Sacramento Orcutt grass (Stone et al. 1988, CNDDB 2002). 
Even though they have not been extirpated, extant occurrences at the 
Phoenix Field Ecological Reserve and the Phoenix Park Vernal Pool 
Preserve have been degraded by off-road vehicles and alterations to 
natural drainage patterns (Clark et al. 1998).
    The remaining pools where Sacramento Orcutt grass grows are subject 
to a wide variety of factors that threaten the species survival. Urban 
encroachment and the associated increase in human activities, is the 
primary factor. One occurrence in the primary area of concentration 
could be destroyed by expansion of the county landfill (Cochrane in 
litt. 1995a); the precise area of expansion has yet to be determined. 
At present, trash from the landfill frequently blows into the pools 
(Cochrane in litt. 1995b). An industrial park and road widening 
threaten another one of the occurrences in the same area (Stone et al. 
1988, Cochrane in litt. 1995a).
    Competition from native plants such as pale spikerush (Heleocharis 
sp.) and mannagrass (Glyceria sp.) could displace Sacramento Orcutt 
grass (Stone et al. 1988, Cochrane in litt. 1995a, Cochrane in litt. 
1995b, Clark et al. 1998). Livestock grazing during the growing season, 
or overstocking during winter grazing, may degrade habitat for 
Sacramento Orcutt grass; however, grazing may be useful in providing 
control of competing plants if appropriate timing and stocking rates 
can be determined (Griggs 1977, Stone et al. 1988, Cochrane in litt. 
1995b).

Sacramento Orcutt Grass Unit Review

    We conducted a regional review across the range of Sacramento 
Orcutt grass to evaluate and select areas that are essential to the 
conservation of the species and that may require special management. 
Important factors we considered were the known presence of the species 
and the presence of the primary constituent elements essential to the 
conservation of the species. A specific description of each area is 
outlined below.

Unit 1, Phoenix Field and Phoenix Park Unit, Sacramento County (29 ha 
(72 ac))

    This unit is proposed as critical habitat for Sacramento Orcutt 
grass because it supports 25 percent of the known occurrences (2 of 8), 
including occurrences found within vernal pools on Red Bluff and 
Redding soils (CNDDB 2002). These pool types provide the necessary 
timing and frequency of inundation for Sacramento Orcutt grass 
germination, growth, and reproduction. The unit boundary was drawn to 
include Sacramento Orcutt grass and the vernal pool complexes in which 
it occurs (Holland 1998, Sacramento County 1999). SPOT imagery was used 
to exclude urban and developed areas, however, the resolution of this 
imagery did not permit us to exclude all developed areas. This unit 
represents the northern extent of the species range, and one of only 
three areas where Sacramento Orcutt grass is known to occur.
    The Phoenix Field Ecological Reserve and Phoenix Park occurrences 
are affected by excess runoff from lawns, baseball fields, and roads; 
by herbicide and fertilizer applied in adjacent areas (Griggs and Jain 
1983, Holland in litt. 1986, Stone et al. 1988, Cochrane in litt. 
1995a, Morey in litt. 1996, Clark et al. 1998); and by dumping of 
landscape waste (Clark et al. 1998). Another threat at the Phoenix 
Field Ecological Reserve is invasion of garden plants (Clark et al. 
1998). Recreational activities such as rollerblading (Witham in litt. 
2000a), biking, and horseback riding (Cochrane in litt. 1995a, Cochrane 
in litt. 1995b, Clark et al. 1998) also are damaging the Phoenix Park 
occurrence.
    This unit is situated within the City of Fair Oaks, and lies east 
of Hazel Avenue and northwest of Lake Natoma. This unit is bounded by 
urban development except for the east side, which is adjacent to Folsom 
Lake State Recreation Area. The City of Fair Oak's Phoenix Park, 
Phoenix Field, and Jim David Park are included within the boundaries of 
this unit. The unit consists primarily of public land and is frequently 
visited by the public. Although surrounded by development, this unit 
represents an important urban preserve for the species.

Unit 2, Southeast Sacramento Valley Unit, Rancho Cordova, Sacramento 
County (8,853 ha (21,875 ac))

    This unit is proposed as critical habitat for Sacramento Orcutt 
grass because it contains over 50 percent of the known occurrences (4 
of 8) of the species within vernal pools on Redding and Redbluff soils 
that contain the primary constituent elements essential for the 
conservation of the species (USDA 2001, Holland 1998, Sacramento County 
1999, CNDDB 2002). This unit also represents one of only three units 
for the species across its entire range. This unit includes relatively 
undisturbed, hydrologically intact vernal pool habitats as mapped by 
Holland (1998), that may continue to support natural vernal pool 
ecosystem processes and maintain suitable habitat conditions for 
Sacramento Orcutt grass to complete germination and reproduction.
    The Southeastern Sacramento Valley Unit for Sacramento Orcutt grass 
occupies the area south and east of Mather Airport and Regional Park. 
The Cosumnes River forms part of the southern and eastern boundary of 
the unit. Urban areas in the cities of Sacramento and Rosemont form the 
western boundary. Mather Airport and the dredge tailings northeast of 
the airport form the northern boundary. The boundaries of this unit 
were delineated to include the interconnected pools, swales, and 
associated uplands mapped by Holland (1998) that contribute to the 
filling and drying of the vernal pools where the species occur, and 
maintain suitable periods of pool inundation, water quality, and soil 
moisture for Sacramento Orcutt grass germination and reproduction.
    The majority of the lands included within this unit are privately 
owned, including the Sunrise Douglas mitigation area, where several 
occurrences of Sacramento Orcutt grass are known to occur. Other vernal 
pool habitats in this area have been identified by the Sacramento 
Valley Open Space Conservancy, the CNPS, and TNC as excellent examples 
of vernal pool grasslands, supporting a rich and diverse community of 
vernal pool endemic plants and animals within Sacramento County. Vernal 
pool habitats in this unit are threatened by urbanization from the 
expanding cities of Sacramento and Elk Grove.

[[Page 59958]]

Conversion to intensive agriculture, particularly vineyards, is also a 
significant threat to Sacramento Orcutt grass habitat in this unit. The 
unit is bisected by the Folsom South Canal and State Highway 16. This 
unit is included in Unit 8 for vernal pool tadpole shrimp and Unit 13 
for vernal pool fairy shrimp and coincides with Unit 6 for slender 
Orcutt grass. Other sensitive vernal pool species located within this 
unit include California linderiella, legenere, Bogg's Lake hedge-
hyssop, Ahart's dwarf rush, and western spadefoot toad.

Unit 3, Rancho Seco Unit, Sacramento and Amador Counties (15,750 ha 
(38,918 ac))

    This unit is proposed as critical habitat for Sacramento Orcutt 
grass because it supports occurrences of the species within high 
terrace vernal pools on Corning soils that contain the primary 
constituent elements and provide the necessary timing and frequency of 
ponding that allow the species to germinate and reproduce (Holland 
1998, USDA 2001, Sacramento County 1999, CNDDB 2002). This unit 
represents one of only three areas where this species is known to 
occur, and is the southern extent of the species range. All of these 
areas are essential to the species by improving its chances of 
surviving natural and environmental changes, as well as random or 
stochastic events. This unit includes relatively undisturbed, 
hydrologically intact vernal pool habitats, that may continue to 
support natural vernal pool ecosystem processes and maintain suitable 
habitat conditions for the species.
    The western boundary of the unit was defined by the extent of high 
terrace soils in the region, including Corning and Redding soils, which 
generally comprise the extent of Sacramento Orcutt grass habitat. The 
northern and southern boundaries of this unit were delineated to 
exclude urban and agricultural areas. The majority of land within this 
unit is privately owned. Some vernal pool areas are protected in this 
unit on TNC's Howard Ranch Preserve and Schnider property near Meiss 
Road. The Clay Station Mitigation Bank and the Borden Ranch mitigation 
site are located within this unit, as well as a number of smaller 
conservation areas including the Rancho Seco Preserve and the L.V. 
Island Preserve. Approximately 247 ha (610 ac) is owned by the CDFG, 
and 3,094 ha (7,736 ac) by TNC. An additional 5 ha (11 ac) of private 
land is protected by WRP easements or agreements. Urban expansion and 
conversion to vineyards threaten existing vernal pool habitats 
throughout this unit.
    This unit occupies the area south of Laguna Creek and north of the 
Sacramento and San Joaquin county line along Dry Creek. The eastern 
boundary is the low elevation foothills of western Amador County. The 
western limit is bounded by urban and agricultural areas near the 
cities of Galt and Elk Grove and along the foothill region of the 
southeastern Sacramento Valley. This unit is a portion of Unit 13 for 
vernal pool tadpole shrimp and Unit 19 for vernal pool fairy shrimp. 
Other sensitive species found within this unit include Bogg's Lake 
hedge-hyssop, Ahart's dwarf rush, Henderson's bent grass, legenere, 
Sanford's arrowhead, pincushion navarretia, dwarf downingia, California 
tiger salamander, western spadefoot toad, and California linderiella.

San Joaquin Valley Orcutt Grass Criteria

    In proposing critical habitat units for San Joaquin Valley Orcutt 
grass we evaluated the life history and current distribution of the 
species, the primary constituent elements, and the current threats to 
the species. This information allowed us to determine which areas are 
most likely to contribute to the conservation of this species.
    San Joaquin Valley Orcutt grass is restricted to the foothills of 
the southern Sierra foothill region of the San Joaquin Valley. Of the 
47 occurrences of San Joaquin Valley Orcutt grass ever reported, 27 are 
presumed to be extant; 17 are certainly extirpated and 3 others are 
possibly extirpated because the habitat has been modified (CNDDB 2001). 
However, only 12 of the occurrences presumed extant have been revisited 
within the past decade, so even the most recent information is 
outdated. This species has been completely extirpated from Stanislaus 
County but remains in Fresno, Madera, Merced, and Tulare counties 
(Stone et al. 1988, CNDDB 2001).
    San Joaquin Valley Orcutt grass does not occur outside of the 
Southern Sierra Foothills Vernal Pool Region (Keeler-Wolf et al. 1998). 
The primary area of concentration is northeast of Merced in Merced 
County, with 14 occurrences (52 percent) on the Flying M Ranch and 
adjacent lands (EIP Associates 1999, Witham in litt. 2000b, CNDDB 
2001). The Lanes Bridge area of Madera and Fresno counties has the 
second highest concentration of San Joaquin Valley Orcutt grass, with 
seven occurrences (26 percent), including the introduced population. 
The remaining six occurrences include three in the Le Grand area of 
Merced County, two on the tabletops near the San Joaquin River in 
Madera and Fresno counties, and one in northwestern Tulare County 
(Stone et al. 1988, Stebbins et al. 1995, CNDDB 2001).
    All of the habitat of San Joaquin Valley Orcutt grass in Stanislaus 
County and much of that in Madera and Fresno counties has been 
converted to irrigated agriculture, especially to almond orchards and 
vineyards (Stone et al. 1988, CNDDB 2001). The majority of sites were 
converted by the late 1970's (Griggs 1980, Griggs and Jain 1983). 
Altered hydrology and development (residential, commercial, and 
recreational) eliminated several other populations (Stone et al. 1988, 
CNDDB 2001). Dryland grain farming has modified vernal pool habitats of 
San Joaquin Valley Orcutt grass in Madera and Merced counties, and the 
species is presumed to be extirpated from those occurrences (CNDDB 
2001). However, Crampton (1959, 1976) indicated that San Joaquin Valley 
Orcutt grass could persist despite dryland farming, and the species was 
rediscovered at one such site after having been absent for several 
years (CNDDB 2001). Summer livestock grazing or heavy use by cattle 
damaged two populations each in Madera and Merced counties (Stone et 
al. 1988, CNDDB 2001); their current status is not known.
    The primary threats facing the remaining occurrences of San Joaquin 
Valley Orcutt grass are altered livestock grazing regimes, agricultural 
conversion, and small population size (Stone et al. 1988, CNDDB 2001). 
Most extant populations are grazed currently. According to Stone et al. 
(1988), moderate cattle grazing in spring is compatible with 
persistence of San Joaquin Valley Orcutt grass, and possibly 
beneficial, but increased stocking rates or summer or year-round 
grazing would be detrimental. Conversion to irrigated agriculture is 
most likely at sites that currently are dry-farmed. Small populations 
are at risk of extirpation due to chance events (Menges 1991), 
particularly those that fluctuate greatly from year to year (Thomas 
1990). Omitting those described only as ``abundant,'' population size 
has been estimated for 14 occurrences of San Joaquin Valley Orcutt 
grass. Three numbered fewer than 10 plants each, even in favorable 
years (Stone in litt. 1992, Stebbins et al. 1995, CNDDB 2001).
    Additional threats to San Joaquin Valley Orcutt grass are varied. 
Four of the extant occurrences in Madera County are in the path of the 
proposed extension of State Highway 41 (Stone in

[[Page 59959]]

litt. 1992). Three other occurrences in Madera and Fresno counties are 
threatened by a proposed residential development (Stone et al. 1988, 
Stebbins et al. 1995, CNDDB 2001). One occurrence could be destroyed by 
construction of the proposed UC campus in Merced County (EIP Associates 
1999). Altered hydrology, competition from other plants, and off-road 
vehicles are potential threats at a few sites (Stone et al. 1988). 
Foraging by grasshoppers (family Acrididae) and mice (order Rodentia) 
occasionally poses problems (Stebbins et al. 1995, CNDDB 2001). In some 
years, grasshoppers (family Acrididae) consumed entire populations of 
San Joaquin Valley Orcutt grass before they set seed (Griggs and Jain 
1983, Stone et al. 1988).

San Joaquin Valley Orcutt Grass Unit Review

    We conducted a regional review of the known range of San Joaquin 
Valley Orcutt grass to evaluate and select areas that are essential to 
the conservation of San Joaquin Valley Orcutt grass and that may 
require special management. Important factors we considered were the 
presence of the species and the presence of the primary constituent 
elements essential to the conservation of the species. A specific 
description of each area is outlined below.

Unit 1, Merced Unit, Merced and Mariposa Counties (45,643 ha (112,783 
ac))

    This unit is proposed as critical habitat for San Joaquin Valley 
Orcutt grass because it supports over half of the known occurrences of 
the species (CNDDB 2001). This unit contains the only area where San 
Joaquin Valley Orcutt grass is found on vernal pools formed upon 
Corning and Greenfield soils, and one of only two sites where it is 
found on San Joaquin soils (Holland 1998, USDA 2001, EIP 1999). These 
pool types maintain the timing and length of inundation necessary for 
San Joaquin Orcutt grass germination, growth, and reproduction, and 
provide a diversity of habitats for the species. This unit supports 
some of the largest, most robust occurrences of the species (Holland 
2000). The area within this unit encompasses the largest block of 
pristine, high density vernal pool grasslands remaining in California 
(Vollmar 1999).
    A majority of the land in the Merced Unit is privately owned and is 
used to graze cattle. Two occurrences on the Flying M Ranch are 
protected under a conservation easement with TNC. The integrity of the 
vernal pool complexes in eastern Merced is seriously threatened by 
irrigated agriculture, upland housing development, and the proposed UC 
Merced Campus and associated development. Construction of facilities to 
educate and serve twenty-five thousand UC students as well as faculty, 
staff, and their families within what is now high quality vernal pool 
habitat in eastern Merced County could have a major impact on species 
endemic to vernal pools. However, the recent draft biological opinion 
for the UC Merced campus and community developed environmental 
parameters which should reduce impacts to vernal pool habitats. 
Indirect and cumulative impacts of the proposed 1,673 ha (4,133 ac) 
campus and associated community may be minimized with the creation of a 
2,036 ha (5,030 ac) preserve intended to protect sensitive vernal pool 
habitat, to be purchased with money donated by the Packard Foundation. 
Approximately 419 ha (1,048 ac) of this unit is owned by the DOD, 4 ha 
(8 ac) by BLM, 10 ha (26 ac) by California State Parks. TNC has 3,424 
ha (8,559 ac) of easement lands within this unit. The remaining lands 
within this unit are privately owned.
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery. A majority of the vernal pool habitat 
in the Merced Unit is in Merced County, although the eastern edge of 
the unit overlaps into Mariposa County in the low elevation foothills 
of the Sierra Nevada. The northern boundary parallels the Merced River, 
and Bear Creek serves as the southern border. The entire unit is 
located east of State Highway 99. The Merced Unit coincides with vernal 
pool tadpole shrimp Unit 15 and vernal pool fairy shrimp Unit 22. It 
also overlaps hairy Orcutt grass Unit 6, Greene's tuctoria Unit 7, 
succulent owl's-clover Unit 3B, Colusa grass Unit 6, and Conservancy 
fairy shrimp Unit 6. Other sensitive vernal pool species found within 
this unit include the California tiger salamander, shining navarretia, 
dwarf downingia, Bogg's Lake hedge-hyssop, western spadefoot toad, and 
California linderiella.

Unit 2, Le Grand Unit, Merced, Mariposa, and Madera Counties (21,495 ha 
(53,114 ac))

    This unit is proposed as critical habitat for San Joaquin Valley 
Orcutt grass because it supports occurrences of the species within 
vernal pools formed on alluvial terraces on Raynor clay soils (CNDDB 
2001). The Le Grand Unit is essential for the conservation of San 
Joaquin Valley Orcutt grass because it contains large intact and 
contiguous vernal pool grassland areas that provide connectivity 
between units to the north and south. This unit contains vernal pools, 
swales, and other ephemeral wetlands and depressions of appropriate 
sizes and depths and the adjacent upland margins of these depressions 
that sustain San Joaquin Orcutt grass germination, growth, 
reproduction, and dispersal. This unit is important to maintain the 
range of habitats in which the species is known to occur.
    This unit contains an area where San Joaquin Valley Orcutt grass 
was introduced into six created pools; it germinated and flowered in 
five of them during the 2 years following its introduction (Durgarian 
1995, Stebbins et al. 1995) and was still present in 2000 (Faubion in 
litt. 2000). This site is now treated as an occurrence by the CNDDB 
(2001). The Madera Irrigation District manages the property, which is 
owned by the BOR (Stebbins et al. 1995). The integrity of vernal pool 
complexes and their associated watersheds in the Le Grand Unit is 
threatened by altered hydrology, competition from other plants, 
irrigated agricultural conversion, particularly orchards and vineyards, 
and urban encroachment. Several occurrences in this unit have been 
extirpated as a result of intensive agriculture.
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery. A majority of the vernal pool habitat 
in the Le Grand Unit is in Merced County. The eastern edge of the unit 
overlaps into Mariposa County and in the south it extends to the Madera 
County line. Bear Creek serves as the northern boundary. The entire 
unit is located east of State Highway 99. The towns of Le Grand and 
Planada are adjacent to the western edge of the unit. The Le Grand Unit 
overlaps with vernal pool tadpole shrimp Unit 15, Greene's tuctoria 
Unit 6, Conservancy fairy shrimp Unit 6, and succulent owl's-clover 
Unit 6. Other sensitive vernal pool species found within this unit 
include California tiger salamander, shining navarretia, and western 
spadefoot toad. TNC has 428 ha (1,070 ac) of easement lands within this 
unit. The remaining lands within this unit are privately owned.

Unit 3, Madera Unit, Madera County (20,937 ha (51,733 ac))

    This unit is proposed as critical habitat for San Joaquin Valley 
Orcutt grass because it supports occurrences of the species within 
alluvial terrace

[[Page 59960]]

vernal pools that provide the necessary timing and length of inundation 
for San Joaquin Valley Orcutt grass germination, growth, and 
reproduction (CNDDB 2001). This area is the only location where the 
species is found on Cometa and San Joaquin soils (USDA 2001).
    San Joaquin Valley Orcutt grass is known from only eight general 
areas along the eastern margin of the San Joaquin Valley. Historically, 
vernal pools spanned from the low elevation Sierra Nevada foothills to 
the valley floor where they connected with other large vernal pool 
complexes. Today, only a fraction of the vernal pool habitat that was 
historically in the greater watershed area remains. The integrity of 
vernal pool complexes and their associated watersheds in the Madera 
Unit is threatened by altered hydrology, competition from other plants, 
irrigated agricultural conversion, particularly orchards and vineyards, 
and urban encroachment.
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery. Located in Madera County, this unit 
contains vernal pool habitat south of the Chowchilla River and abutting 
the Fresno River. Berenda Creek is located northwest of the unit. 
Habitat within this unit is located east of the Atchison, Topeka, and 
Santa Fe Railroad and extends into the low elevation foothill region of 
the Sierra Nevada. The town of Madera borders the unit on its southwest 
edge, Hensley Lake is east of the unit, and Eastman Lake is northeast 
of the unit. The Madera Unit coincides with hairy Orcutt grass Unit 7, 
Greene's tuctoria Unit 7, succulent owl's-clover Unit 4 and vernal pool 
fairy shrimp Unit 24A. Other sensitive vernal pool species found within 
this unit include California tiger salamander and California 
linderiella. All the land within this unit is privately owned.

Unit 4, Fresno Unit, Fresno County (3,233 ha (7,990 ac))

    This unit is proposed as critical habitat for San Joaquin Valley 
Orcutt grass because it contains occurrences of the species growing 
within vernal pools formed on Fallbrook, Ramona, San Joaquin, Vista, 
and Pollasky soil series (CNDDB 2002). This unit contains vernal pools, 
swales, and other ephemeral wetlands and depressions of appropriate 
sizes and depths and the adjacent upland margins of these depressions 
that sustain San Joaquin Orcutt grass germination, growth, and 
reproduction. This unit is significant geographically, as it may 
contribute to dispersal to vernal pool habitats north and south of it. 
The diversity of vernal pool types found within the Fresno Unit 
contributes to the range of ecological conditions in which San Joaquin 
Valley Orcutt grass occurs.
    Due to edaphic variation, vernal pool habitat in this unit is less 
dense than habitat in units further north. Vernal pools within this 
unit have been destroyed by conversion to irrigated agriculture, as 
well as urban encroachment from the cities of Fresno and Clovis. 
Several known occurrences of San Joaquin Valley Orcutt grass within 
this unit have been extirpated due to either hydrologic modifications 
off-site, or land use modifications such as leveling of ``hog wallows'' 
for urban development such as near State Route 41 near Woodward Park in 
Fresno.
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery. Located in Fresno County, this unit 
contains vernal pool habitat south of Millerton Lake and east of the 
San Joaquin River. The unit is located north of Copper Road and the 
city of Fresno is southwest of the unit. The eastern boundary parallels 
the low elevation foothill region of the Sierra Nevada. Auberry Road is 
east of the northern portion of the unit and passes through the 
southern portion of the unit. CDFG has approximately 0.4 ha (1 ac) of 
land within this unit. The Fresno Unit overlaps San Joaquin Valley 
Orcutt grass Unit 5 and vernal pool fairy shrimp Unit 24B. Other 
sensitive vernal pool species found within this unit include California 
linderiella, California tiger salamander, and western spadefoot toad.

Unit 5 A and B, Table Mountain Unit, Fresno and Madera Counties, (1,723 
ha (4,258ac))

    This area is proposed as critical habitat for San Joaquin Valley 
Orcutt grass because it supports occurrences of the species within 
Northern Basalt Flow vernal pools (Holland 1998, Keeler-Wolf et al. 
1998, CNDDB 2002). This is the only area where San Joaquin Valley 
Orcutt grass is known to occur within these pool types (CNDDB 2001). 
Northern Basalt Flow vernal pool complexes are an extremely rare vernal 
pool habitat occurring only on ancient terraces and hilltops above the 
surrounding low-lying terrain. They typically contain small, 
irregularly clustered pools with ``flashy hydrology'' (Keeler-Wolf et 
al. 1998). The Kennedy Table occurrence of San Joaquin Valley Orcutt 
grass was described as containing millions of plants in 1995 (CNDDB 
2001).
    This unit contains protected lands at the Big Table Mountain 
Ecological Reserve. A cooperative group consisting of CDFG, California 
Department of Parks and Recreation, Sierra Foothill Conservancy, BLM, 
and BOR has developed a management and monitoring plan for Big Table 
Mountain. BLM owns approximately 15 ha (370 ac) of land and TNC has 260 
ha (650 ac) of conservation easements within this unit. Initial efforts 
will focus on grazing as a means to control non-native grasses while 
comparing population trends of threatened and endangered species in 
grazed and ungrazed portions of the tableland (Griggs in litt. 2000a). 
This unit also contains an occurrence of San Joaquin Valley Orcutt 
grass that is partially on public land administered by the BLM. The 
pool supports the second-largest population of the species known to be 
extant. The BLM and conservation groups are hoping to acquire the 
adjacent land to protect the entire pool (CNDDB 2001).
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery, as well as elevation contours in the 
eastern foothill region and sub-watershed boundaries. Unit 5 for San 
Joaquin Orcutt grass is comprised of two subunits. Both subunits are 
located east of Millerton Lake on basalt mesas above the San Joaquin 
River. Subunit 5B is located on Kennedy Table in Madera County, and 
Subunit 5A is directly south of this unit across the San Joaquin River 
on Table Mountain in Fresno County. The Table Mountain Rancheria is 
south of this unit. Unit 5 coincides with vernal pool fairy shrimp Unit 
25, vernal pool tadpole shrimp Unit 17, and succulent owl's-clover 
units 6A and 6B. Other sensitive vernal pool species found within this 
unit include Bogg's lake hedge-hyssop and California linderiella.

Unit 6A and B, Tulare Unit, Tulare County (8,028 ha (19,836 ac))

    This unit is proposed as critical for San Joaquin Valley Orcutt 
grass because it contains occurrences of the species within vernal 
pools on Madera and Greenfield soils that provide the primary 
constituent elements essential to the conservation of the species (USDA 
2001, CNDDB 2001). This unit represents the southern extent of San 
Joaquin Valley Orcutt grass range. San Joaquin Valley Orcutt grass 
occurs on CDFG land at Sequoia Fields Ecological Reserve (199 ha, (491 
ac)); however, most of the area within this unit is

[[Page 59961]]

privately owned. This unit contains vernal pools and other ephemeral 
wetlands and depressions of appropriate sizes and depths and the 
adjacent upland margins of these depressions that sustain San Joaquin 
Valley Orcutt grass germination, growth and reproduction. Agricultural 
conversion of range or barren land and urban development have greatly 
reduced the amount of vernal pool habitat in this area.
    The unit boundary was drawn to include species occurrences and the 
vernal pool complexes in which they occur as mapped by Holland (1998) 
and as visible on SPOT imagery, as well as elevation contours in the 
eastern foothill region and sub-watershed boundaries. There are two 
subunits within the Tulare Unit. This westernmost subunit, subunit A, 
is located east of J19. Road 63 cuts through its eastern edge. St. 
Johns River is south of the subunit and the Southern Pacific Railroad 
runs northeast of the unit. Subunit B is located east of Road 63 and 
Road 201 passes through it. It extends into the low elevation foothills 
of the Sierra Nevada. Colvin Mountain is located within the southwest 
boundary. Road 245 bisects subunit B and the south side of Red Mountain 
is within the northeast boundary of this unit. The Tulare Unit 
coincides with Hoover's spurge Unit 7, and it overlaps with vernal pool 
tadpole shrimp Unit 18 and vernal pool fairy shrimp Unit 26. Other 
sensitive vernal pool species found within this unit include California 
tiger salamander, spiny-sepaled button-celery, and the western 
spadefoot toad.

Slender Orcutt Grass Criteria

    In proposing critical habitat units for slender Orcutt Grass we 
evaluated the life history and current distribution of the species 
described in the background section of this rule, the primary 
constituent elements described in the primary constituent element 
section of this rule, and the current threats to the species described 
below. This information allowed us to determine which areas are likely 
to contribute to the conservation of this species and to delineate 
units so that threats to this species might be minimized.
    Slender Orcutt grass is currently known from 79 occurrences, of 
which 73 are presumed to be extant (Corbin in litt. 1999, CNDDB 2001); 
occurrences are presumed to be extant until the CNDDB receives 
documentation that they have been extirpated. The primary area of 
concentration for slender Orcutt grass is in the vicinity of Dales, 
Tehama County. A secondary area of concentration for slender Orcutt 
grass is the Modoc Plateau Vernal Pool Region in Lassen, Plumas, 
Shasta, and Siskiyou counties. Additional occurrences of the species 
are found in Shasta, Lake, and Sacramento counties.
    Urban development in the vicinity of Redding has extirpated or 
caused the severe decline of five slender Orcutt grass occurrences 
through construction activities and hydrological alterations (Griggs 
and Jain 1983, CNDDB 2001). Agricultural conversion apparently 
eliminated the species from the type locality. Although the exact 
location of the type collection is not known, the general area was 
being used for crop fields and both irrigated and dry pastures as of 
1987 (Stone et al. 1988). Urban development is continuing in the 
vicinity of Redding and could eliminate the remaining populations in 
that area.
    A variety of other factors are contributing to the continued 
decline of slender Orcutt grass including off-road vehicle use, 
inappropriate livestock grazing, altered hydrology, and competition 
from other plants (Stone et al. 1988, Corbin and Schoolcraft 1989). 
Off-road vehicle use is a particular problem near Redding and in 
forested areas of the Modoc Plateau. According to Stone et al. (1988), 
``moderate'' livestock grazing in spring is compatible with slender 
Orcutt grass but overstocking, summer grazing, and trampling pose 
threats to several occurrences. However, grazing may be necessary to 
control aggressive competitors such as the native species, pale 
spikerush (Witham in litt. 2000a). Altered hydrology contributes to the 
decline of slender Orcutt grass by creating conditions unsuitable for 
its germination, growth, or reproduction, and by promoting the growth 
of competing plant species.

Slender Orcutt Grass Unit Review

    We conducted a regional review across the range of slender Orcutt 
grass to evaluate and select areas that are essential to the 
conservation of the species and that may require special management. 
Important factors we considered were the known presence of the species 
and the presence of the primary constituent elements essential to the 
conservation of the species. A specific description of each area is 
outlined below.

Unit 1 A, B, C, D, E, F, G, H, and I, Modoc Plateau Unit, Plumas, 
Lassen, Shasta, Modoc, and Siskiyou Counties (23,266 ha (57,490 ac))

    This unit is proposed as critical habitat for slender Orcutt grass 
because it contains almost 25 percent of all known occurrences of the 
species and the vernal pool habitat remains inundated for sufficient 
periods of time to allow slender Orcutt grass to complete its life 
cycle. The species is found growing within Northern Basalt Flow vernal 
pools occurring on Gooval, Lasvar, Lasvar-Pitvar, and Nosoni soils that 
provide the primary constituent elements essential to the conservation 
of the species (CNDDB 2002). These occurrences are all found on the 
Modoc Plateau, where they are located at higher elevations, and 
experience the coldest climatic conditions of any other areas 
throughout the species range. The occurrences are on Northern Basalt 
Flow vernal pools (CNDDB 2002). This area represents the northern-most 
extent of the range of slender Orcutt grass, and is over 50 km (32 mi) 
from the nearest occupied areas to the south.
    The boundaries of this unit were delineated by using SPOT imagery 
and elevation contours to include the open flat area associated with 
the vernal pool including the adjacent uplands that contribute to the 
filling and drying of the vernal pool where slender Orcutt grass 
occurs. The unit designates an area sufficient to maintain suitable 
periods of pool inundation, water quality, and soil moisture for 
slender Orcutt grass to germinate, grow, and reproduce.
    The Modoc Plateau area is not threatened by urban development at 
this time due to its remote location, however off-road vehicle use and 
overgrazing may threaten some occurrences in this area (CNDDB 2001). 
Additional sensitive species found within this unit include Bogg's Lake 
hedge-hyssop, and profuse flowered pogogyne (Pogogyne floribunda). 
Although the majority of land within this unit is located either on 
USFS (15,500 ha (38,750 ac)), NPS (58 ha (144 ac)), or BLM lands (2,754 
ha (6,886 ac)). The California State Parks also has land within this 
unit (37 ha (92 ac)).
    This unit for slender Orcutt grass consists of nine subunits 
largely within the volcanic plateau of northeastern California. The 
nine subunits are identified as the Lake Almanor, Crater Lake Mountain, 
Poison Lake, Badger Mountain, Lost Creek, Goose Valley, Long Valley, 
Cayton Creek, and Timbered Crater subunits. The Lake Almanor subunit is 
located in Plumas County, on the southwestern part of Lake Almanor 
along Humbug Humboldt Cross Road and State Route 89. The area extends 
from near the shoreline upslope to the watershed boundary. The land is 
owned by the USDA and managed by the USFS. The Crater Lake Mountain 
subunit is located along Route 44 and encompasses the northwestern 
portion of Crater Lake Mountain as well as

[[Page 59962]]

Grays and Harvey valleys. The watershed boundary was used to determine 
the extent of this subregion. The Poison Lake subunit north of State 
Route 44 near Pittville Road adjacent to South Cabin Reservoir and Ebey 
Lake. The western boundary is near Halls Flat Road. The Badger Mountain 
subunit is located north of Badger Mountain and east of State Route 89 
and South of Potato Butte. Little Bunch Grass Meadow is included in 
this unit. The Lost Creek subunit is located south of Cinder Butte and 
west of the Hat Creek Rim. Lost Creek near Wilcox Road is within this 
subunit. The Goose Valley subunit is located in Shasta County northwest 
of the intersection of State Route 299 and Route 89 in Goose Valley 
north of Burney, California. The Long Valley subunit is located in Long 
Valley west of Black Ranch Road south of Long Valley Mountain and east 
of Lookout Mountain. The Cayton Creek subunit is located in Shasta 
County north of Cayton Valley and Lake Britton east of Route 89. The 
area includes the northwestern portion of the watershed boundary for 
Fort Mountain along Red Mountain Road. The subunit is located in the 
Shasta National Forest. The Timbered Crater subunit is located on the 
Shasta/Modoc/Siskiyou county border near Little Hot Springs Valley. The 
subunit includes the area adjacent to Timbered Crater up to the 
Whitehorse Mountains and Day Road. The Timbered Crater subunit includes 
an area which has been proposed to be designated by the BLM as a 
Research Natural Area for vernal pools.

Unit 2 A, B, and C, Stillwater Plains Unit, Shasta County (5,100 ha 
(12,601 ac))

    This unit is proposed as critical habitat because it contains many 
occurrences of slender Orcutt grass (CNDDB 2001) living within large 
vernal pool grassland areas that support aggregations or systems of 
hydrologically interconnected pools, swales, and other ephemeral 
wetlands and depressions within a matrix of surrounding uplands that 
together form hydrologically and ecologically functional units (EPA 
1994, Holland 1998, Shasta County 2001).
    This area is comprised of old alluvial terraces above the 
Sacramento River associated with Igo, Tuscan, Moda, and Redding soils 
(CNDDB 2001), which provide vernal pool habitat for the species. These 
pool types provide the necessary timing and duration of inundation 
necessary for slender Orcutt grass growth, germination, and 
reproduction. This unit represents the northern extent of the species 
range in the Sacramento Valley. The majority of the lands included 
within this unit are privately owned. Urban expansion from the city of 
Redding has greatly affected existing vernal pool habitats throughout 
this unit.
    The boundaries of this unit were delineated to include the 
interconnected pools, swales, and associated uplands mapped by Holland 
(1998) that contribute to the filling and drying of the vernal pools 
where the species occur, and maintain suitable periods of pool 
inundation, water quality, and soil moisture for slender Orcutt grass 
germination and reproduction. The BLM owns 33 ha (81 ac) in the unit, 
while the NRCS holds conservation easements or agreements on an 
additional 52 ha (130 ac) through its WRP program.
    The Stillwater Plains Unit 2 contains three subunits. These are 
located in the area east and south of the city of Redding near the 
Redding Municipal Airport encompassing Stillwater Plains to the 
confluence of the Sacramento River and Cow Creek. This unit is also 
part of vernal pool fairy shrimp Unit 5 and vernal pool tadpole shrimp 
Unit 1. Other sensitive species occurring within this unit include Red 
Bluff dwarf rush, California linderiella, and Henderson's bent grass.

Unit 3, Inskip Hill, Tehama and Shasta Counties (20,446 ha (50,522 ac))

    This unit is proposed as critical habitat for slender Orcutt grass 
because it supports occurrences of the species within vernal pools on 
Guenon, Inskip, Inks, and Toomes soils (CNDDB 2002). The vernal pool 
habitats remain inundated for sufficient periods of time to allow the 
species to germinate, grow, and produce seed. The area supports over 40 
percent of the known occurrences the species (CNDDB 2002) and is 
important in maintaining a diversity of habitats for slender Orcutt 
grass. This unit contains large vernal pool complexes that represent 
some of the last remaining lower elevation vernal pool habitats in the 
northern Sacramento Valley. These habitats are important to maintain 
the geographical distribution of slender Orcutt grass in the area.
    The boundaries of this unit were delineated to include the 
interconnected pools, swales, and associated uplands mapped by Holland 
(1998) that contribute to the filling and drying of the vernal pools 
where the species occur, and maintain suitable periods of pool 
inundation, water quality, and soil moisture for slender Orcutt grass 
germination and reproduction.
    Land ownership within this unit includes BLM (6,226 (15,384 ac)), 
CDFG (52 ha (130 ac)), State Land Commission (380 ha (950 ac)). The 
CDFG administers approximately 17 ha (42 ac) and the TNC has 
conservation easements on 6,230 (15,575 ac) within this unit. The 
remaining lands included within this unit are privately owned and urban 
development east of Redding threatens the vernal pool habitats within 
this area. This unit occupies the area south of the Tehama/Shasta 
county line south to Sevenmile Creek near the Tuscan Buttes. The 
eastern boundary encompasses the vernal pool habitats along the lower 
elevation bordering the Sacramento River. The western boundary roughly 
follows the Sacramento River. Table Mountain west of the Sacramento 
River north of Paynes Creek and Red Bluff is included in this unit. 
This unit coincides within Unit 2 for vernal pool tadpole shrimp.

Unit 4, Vina Plains Unit, Tehama and Butte Counties (11,673 ha (28,845 
ac))

    This unit is proposed as critical habitat for slender Orcutt grass 
because it supports occurrences of the species within vernal pools on 
Tuscan loam and Inks soils (CNDDB 2002) and the vernal pool habitats 
provide the necessary timing and length of inundation for slender 
Orcutt grass germination, growth, and reproduction. This area is over 
160 km (100 mi) from the nearest area occupied by slender Orcutt grass 
to the south.
    The boundaries of this unit were delineated by using SPOT imagery 
and elevation contours to include the open flat area associated with 
the vernal pool including the adjacent uplands that contribute to the 
filling and drying of the vernal pools where slender Orcutt grass 
occur, and maintain suitable periods of pool inundation, water quality, 
and soil moisture for slender Orcutt grass to germinate and reproduce.
    The majority of the lands included within this unit are privately 
owned. This unit contains TNC's 1862 ha (4,600 ac) Vina Plains 
preserve. The preserve contains over 300 species of plants, and diverse 
communities of aquatic invertebrates. Since the 1960s, the Vina Plains 
area has been the focus of a number of research projects, including 
long-term adaptive management and monitoring efforts evaluating of the 
effects of grazing and fire on vernal pool plants (Griggs 2000). Much 
of the basic life history information known about slender Orcutt grass 
was collected at Vina Plains (e.g., Stone et al. 1988, Alexander and 
Schlising 1997). The results of this research have provided crucial 
information to guide management and monitoring of vernal

[[Page 59963]]

pool ecosystems and to identify factors which influence population 
dynamics of a number of endangered species, including slender Orcutt 
grass. In addition to TNC, the importance of vernal pool habitats in 
this area has been recognized by the CDFG, the Service, the EPA, the 
CNPS, the NRCS's WRP, and by researchers at the CSU at Chico, who have 
all supported research and conservation efforts for slender Orcutt 
grass and other vernal pool species within this unit. Property 
ownership and protection within this unit includes CDFG (0.4 ha (1 
ac)), CDFG administered land (0.4 ha (1 ac)), TNC (77 ha (192 ac)), TNC 
easements (4,661 ha (11,653)), and private land under WRP easements or 
agreements (57 ha, 142 ac)).
    This unit for slender Orcutt grass occupies the area south of 
Toomes Creek, and north of Pine Creek and the Cana Highway. State Route 
99 bisects this unit and the western boundary generally parallels the 
Southern Pacific Railway line. This unit is within Unit 7 for vernal 
pool fairy shrimp and Unit 3 for vernal pool tadpole shrimp, and 
includes part of Unit 1 for Conservancy fairy shrimp and Unit 1 for 
Hoover's spurge. The unit coincides with Unit 1 for hairy Orcutt grass 
and Unit 2 for Greene's tuctoria. Additional sensitive vernal pool 
species occurring in this unit include California linderiella, and 
Bogg's Lake hedge-hyssop.

Unit 5A and B, Bogg's Lake Unit, Clear Lake Area, Lake County (1,696 ha 
(4,191 ac))

    This unit is proposed as critical habitat for slender Orcutt grass 
because it supports occurrences of the species within Northern Volcanic 
Ashflow vernal pools (Keeler-Wolf et al. 1998, CNDDB 2002). This area 
represents the western extent of the slender Orcutt grass's range, and 
some of the last remaining vernal pool habitats in Lake County. This 
unit is over 135 km (84 mi) from the nearest units to the north and 
west. Isolated and peripheral populations such as this may have genetic 
characteristics essential to the overall long-term conservation of the 
species (i.e., they may be different from other populations in other 
parts of its range) (Lesica and Allendorf 1995). This is the only unit 
which contains examples of Northern Volcanic Ash Flow vernal pools and 
has occurrences of slender Orcutt grass.
    The boundaries of this unit were delineated to include the 
interconnected pools, swales, and associated uplands mapped by Holland 
(1998) that contribute to the filling and drying of the vernal pools 
where the species occur, and maintain suitable periods of pool 
inundation, water quality, and soil moisture for slender Orcutt grass 
germination and reproduction.
    The majority of lands within this unit are privately owned. TNC has 
protected the area around Bogg's Lake south of Clear Lake, but most of 
the area is not protected. Property ownership and protection within 
this unit includes CDFG (5 ha (13 ac)) and TNC (77 ha (192 ac)) lands. 
Threats to these subunits include conversion of rangeland to vineyards, 
overgrazing, erosion, draining, and urban expansion.
    This unit consists of two subunits that are both located south of 
Clear Lake. The southernmost subunit includes Little High Valley. Other 
sensitive species found within this unit include Loch Lomond button-
celery (Eryngium constancei), Burke's goldfields (Lasthenia burkei), 
Bogg's Lake hedge-hyssop, many-flowered navarretia (Navarretia 
leucocephala ssp. plieantha), few-flowered navarretia, and legenere.

Unit 6, Southeast Sacramento Valley Unit, Rancho Cordova, Sacramento 
County (8,853 ha (21,875 ac))

    This unit is proposed as critical habitat for slender Orcutt grass 
because it supports occurrences of the species within vernal pools on 
Redding soils and is the southern extent of the species range (CNDDB 
2001, Holland 1998). This unit is over 170 km (105 mi) from the nearest 
units to the north, and 100 km (62 mi) from the nearest unit to the 
west. Isolated and peripheral populations such as this may have genetic 
characteristics essential to the overall long-term conservation of the 
species (i.e., they may be different from more central populations) 
(Lesica and Allendorf 1995).
    The boundaries of this unit were delineated to include the 
interconnected pools, swales, and associated uplands mapped by Holland 
(1998) that contribute to the filling and drying of the vernal pools 
where the species occur, and to maintain suitable periods of pool 
inundation, water quality, and soil moisture for slender Orcutt grass 
germination and reproduction.
    This unit occupies the area southeast of Mather Field of Laguna 
Creek and north of the Sacramento and San Joaquin county line along Dry 
Creek. The eastern boundary is near Scott Road. The western limit is 
bounded by urban and agricultural areas near the cities of Galt and Elk 
Grove. This unit also is included in Unit 8 for vernal pool tadpole 
shrimp and Unit 13 for vernal pool fairy shrimp and coincides with Unit 
2 for Sacramento Orcutt grass. Other sensitive vernal pool species 
located within this unit include California linderiella, legenere, 
Bogg's Lake hedge-hyssop, Ahart's dwarf rush, and western spadefoot 
toad. All the lands within this unit are privately owned.

Solano Grass Criteria

    In proposing critical habitat units for Solano Grass we evaluated 
the life history and current distribution of the species, the primary 
constituent elements, and the current threats to the species. This 
information allowed us to determine which areas are likely to 
contribute to the conservation Solano grass.
    Solano grass is only known from two locations, Jepson Prairie in 
Solano County, (consisting of two CNDDB occurrences, including the type 
locality) and the Davis Communications Annex in Yolo County. Solano 
grass is presumed to remain extant at the type locality, although only 
four individual plants have been found within the last decade, all in 
1993 (CNDDB 2001). The decline of this species at Olcott Lake is 
attributed to two primary causes--hydrological alterations (Griggs in 
litt. 2000) and over collection (K. Fuller USFWS pers. comm.1998). 
Competition, livestock grazing, and off-road vehicle activity may have 
contributed to its decline (Service 1985c, Witham in litt. 1992, CNDDB 
2001). The hydrology has been affected by the nearby road, Cook Lane, 
which functions like a dam to hold water in the lake, artificially 
increasing the water level and duration of inundation (Griggs in litt. 
2000). The Yolo County habitat has been damaged by application of 
herbicides and salt (Witham in litt. 2000a). An undetermined number of 
Solano grass occurrences are presumed to have been extirpated by 
agricultural conversion before they were documented (Service 1985c, 
CDFG 1991).
    Competition from aggressive plants poses a potential threat to 
Solano grass at all three known sites. The primary competitors are 
lippia at Olcott Lake (Witham in litt. 2000a), alkali mallow and swamp 
grass at the other site in Solano County (CNDDB 2001), and broad-leaved 
pepper-weed (Lepidium latifolium) in Yolo County (K. Fuller 2002 pers. 
comm.). Grazing apparently is detrimental to Solano grass but likely 
depends on the number and type of livestock and the season of use. 
Exclusion of horses from the Olcott Lake site was followed by an 
increase in population size (Service 1985c). At last report, sheep 
still grazed the other Solano County population (CNDDB 2001).

[[Page 59964]]

    A number of factors threaten the Yolo County population in addition 
to competition, including herbicide runoff and soil disturbance from 
the creation and maintenance of fire breaks and borrow pits (CNDDB 
2001, Witham in litt. 2000a). The site is not protected but does occur 
on DOD land.

Solano Grass Unit Review

    We conducted a regional review across the range of Solano grass to 
evaluate and select areas that are essential to the conservation of the 
species and that may require special management. Important factors we 
considered were the known presence of the species and the presence of 
the primary constituent elements essential to the conservation of the 
species. A specific description of each area is outlined below.

Unit 1, Davis Communications Annex and Grasslands Area Unit, Yolo 
County (192 ha (474 ac))

    This unit is proposed as critical habitat for Solano grass because 
it supports the largest extant occurrence of the species within 
Northern Claypan vernal pools on Pescadero soils (CNDDB 2002). The unit 
boundary was drawn to include the vernal pool complex mapped by Holland 
(1998) and Yolo County Parks (2001) where Solano grass is known to 
occur. This vernal pool complex maintains suitable periods of pool 
inundation, water quality, and soil moisture for Solano grass 
germination, growth and reproduction, and dispersal, but not 
necessarily every year. This unit represents the northern extent of the 
range of Solano grass, and is one of only two areas where the species 
is known to occur. Solano grass in this unit is threatened by altered 
hydrology, contamination, competition with invasive plant species, and 
surface disturbances such as discing. This unit is designated to 
encourage that special management actions be taken, such as grazing, 
fencing, and the implementation of a targeted management and monitoring 
plan be implemented to prevent the decline of Solano grass at this 
location (Yolo County Parks 2001).
    This unit is located southeast of the City of Davis and south of 
the South Fork of Putah Creek. This unit's western boundary lies along 
the border between Solano and Yolo counties. This unit represents Unit 
2 for Colusa grass and Unit 10 for vernal pool tadpole shrimp. Other 
rare vernal pool species found in this unit include alkali milk-vetch. 
This area is currently being addressed by local conservation planning 
efforts and contains land owned by Yolo County and the DOD (130 ha (321 
ac)).

Unit 2, Jepson Prairie Unit, Solano County (7,153 ha (17,675 ac))

    This unit is designated as critical habitat for Solano grass 
because it supports occurrences of the species within large playa 
vernal pools on the Pescadero soil series which provide habitat for 
Solano grass (USDA 2001, Holland 1998, Solano County Water Agency 2000, 
Solano County Farmlands and Open Space 2000, CNDDB 2002). This area 
represents the largest contiguous area of habitat remaining for the 
species, and contains two of the three known occurrences of Solano 
grass, although one of these occurrences has not been observed since 
1993. Vernal pool habitats within the greater Jepson Prairie grassland 
area that are not likely to support Solano grass occurrences were not 
included within this unit. This unit represents the southern extent of 
Solano grass range.
    The Jepson Prairie Unit for Solano grass is a portion of the 
greater Jepson Prairie grassland area, one of the most pristine, intact 
vernal pool ecosystems remaining in the State of California. Jepson 
Prairie contains large, playa-like vernal pools which may be over 
several acres in size, including the 32 ha (80 ac) Olcott Lake. These 
larger pools often occur in complexes with smaller pools and hogwallow 
depressions. This unit includes the Jepson Prairie Preserve, jointly 
managed by the Solano County Farmlands and Open Space Foundation and 
the UC Reserve System. Jepson Prairie is the target of ongoing 
conservation planning and active management. As part of the UC Reserve 
System, this area also provides critical research opportunities for 
scientists to study vernal pool species, including Solano grass. Solano 
grass has experienced unexplained declines at Olcott Lake in Jepson 
Prairie, and research investigating the cause of this decline is 
essential to ensure the recovery of Solano grass. The unit also 
contains Ecological Reserves totaling 248 ha (620 ac) owned and 
approximately 64 ha (161 ac) administered by CDFG. Additional lands are 
owned by the Travis Air Force Base (93 ha (233 ac)), and the State Land 
Commission (7 ha (17 ac)). NRCS also holds conservation easements or 
agreements on 436 ha (1,090 ac) of private land in the unit through the 
WRP program. Within the greater Jepson Prairie grassland area, existing 
vernal pools are threatened by agricultural conversion, landfill 
expansion, power plant construction, and utility maintenance.
    This unit is situated east of the City of Fairfield, south of the 
City of Dixon, and north of the Montezuma Hills and the confluence of 
the Sacramento and San Joaquin rivers. This unit coincides with Unit 2 
for Colusa grass. This unit is encompassed by Unit 3 for Conservancy 
fairy shrimp, Unit 11 for vernal pool tadpole shrimp and Unit 16 for 
vernal pool fairy shrimp. This unit also supports a diverse community 
of plants and animals, including the only known occurrence of delta 
green ground beetle, and occurrences of California tiger salamander, 
alkali milk-vetch, Bogg's Lake hedge-hyssop, legenere, California 
linderiella, and midvalley fairy shrimp.

Additional Considerations

    In defining critical habitat boundaries, we made an effort to avoid 
developed areas, such as towns and other similarly developed lands, and 
intensively farmed lands that are unlikely to contribute to 
conservation of the species. However, the resolution of the SPOT 
imagery and the vernal pool and species occurrence information we used 
did not allow us to identify these areas at a sufficiently fine scale 
to exclude all developed areas, such as towns, housing developments, or 
other lands unlikely to contain the primary constituent elements. 
Existing features and structures within the boundaries of the mapped 
units, such as buildings, roads, aqueducts, railroads, airport runways, 
other paved areas, lawns, landscaped areas, and most intensively farmed 
areas, and other urban areas, will not contain one or more of the 
primary constituent elements. Federal actions limited to those areas, 
therefore, would not trigger section 7 consultation, unless they affect 
the species and/or primary constituent elements in adjacent critical 
habitat.

Effects of Critical Habitat Designation

Section 7 Consultation

    Section 7(a) of the Act requires Federal agencies, including the 
Service, to ensure that actions they fund, authorize, permit, or carry 
out do not destroy or adversely modify critical habitat. Destruction or 
adverse modification of critical habitat occurs when a Federal action 
directly or indirectly alters critical habitat to the extent it 
appreciably diminishes the value of critical habitat for the 
conservation of the species. Individuals, organizations, States, local 
governments, and other non-Federal entities are affected by the 
designation of critical habitat only if their actions occur on Federal 
lands, require a Federal permit,

[[Page 59965]]

license, or other authorization, or involve Federal funding.
    Section 7(a) of the Act requires Federal agencies, including the 
Service, to evaluate their actions with respect to any species that is 
proposed or listed as endangered or threatened, and with respect to its 
critical habitat, if any is designated or proposed. Regulations 
implementing this interagency cooperation provision of the Act are 
codified at 50 CFR part 402. Section 7(a)(4) of the Act requires 
Federal agencies to confer with us on any action that is likely to 
jeopardize the continued existence of a species proposed for listing, 
or result in destruction or adverse modification of proposed critical 
habitat. Conference reports provide conservation recommendations to 
assist the action agency in eliminating conflicts that may be caused by 
the proposed action. The conservation measures in a conference report 
are advisory.
    We may issue a formal conference report, if requested by the 
Federal action agency. Formal conference reports include an opinion 
that is prepared according to 50 CFR 402.14, as if the species was 
listed or critical habitat designated. We may adopt the formal 
conference report as the biological opinion when the species is listed 
or critical habitat designated, if no substantial new information or 
changes in the action alter the content of the opinion (50 CFR 
402.10(d)).
    If a species is listed or critical habitat is designated, section 
7(a)(2) of the Act requires Federal agencies to ensure that activities 
they authorize, fund, or carry out are not likely to jeopardize the 
continued existence of such a species or to destroy or adversely modify 
its critical habitat. If a Federal action may affect a listed species 
or its critical habitat, the responsible Federal agency (action agency) 
must enter into consultation with us. Through this consultation, the 
Federal action agency would ensure that the permitted actions do not 
destroy or adversely modify critical habitat.
    If we issue a biological opinion concluding that a project is 
likely to result in the destruction or adverse modification of critical 
habitat, we also provide ``reasonable and prudent alternatives'' to the 
project, if any are identifiable. Reasonable and prudent alternatives 
are defined at 50 CFR 402.02 as alternative actions identified during 
consultation that can be implemented in a manner consistent with the 
intended purpose of the action, that are consistent with the scope of 
the Federal agency's legal authority and jurisdiction, that are 
economically and technologically feasible, and that the Director 
believes would avoid the likelihood of jeopardizing the continued 
existence of listed species, or resulting in the destruction or adverse 
modification of critical habitat. Reasonable and prudent alternatives 
can vary from slight project modification to extensive redesign or 
relocation of the project.
    Regulations at 50 CFR 402.16 require Federal agencies to reinitiate 
consultation on previously reviewed actions under certain 
circumstances, including instances where critical habitat is 
subsequently designated and the Federal agency has retained 
discretionary involvement, or control has been retained, or is 
authorized by law. Consequently, some Federal agencies may request 
reinitiation of consultation or conference with us on actions for which 
formal consultations have been completed, if those actions may affect 
designated critical habitat or adversely modify or destroy proposed 
critical habitat.
    Activities on Federal lands that may jeopardize vernal pool 
crustaceans or vernal pool plants or adversely modify their critical 
habitat will require section 7 consultation. Activities on private 
lands that require a permit from a Federal agency, such as a permit 
from the Corps under section 404 of the Clean Water Act (33 U.S.C. 1344 
et seq.), a section 10(a)(1)(B) of the Act permit from the Service, or 
any other activity requiring Federal action (i.e., funding or 
authorization from the Federal Highways Administration or Federal 
Emergency Management Agency) will also continue to be subject to the 
section 7 consultation process. Federal actions not affecting listed 
species or critical habitat, and actions on non-Federal lands that are 
not federally funded, authorized, or permitted do not require section 7 
consultation. Not all of the areas within these units are capable of 
supporting vernal pool crustaceans or vernal pool plants or their 
primary constituent elements, and such areas would not be subject to 
section 7 consultation.
    To properly portray the effects of critical habitat designation, we 
must first compare the section 7 requirements for actions that may 
affect critical habitat with the requirements for actions that may 
affect a listed species. Section 7 ensures that actions funded, 
authorized, or carried out by Federal agencies are not likely to 
jeopardize the continued existence of a listed species, or destroy or 
adversely modify the listed species' critical habitat. Actions likely 
to jeopardize the continued existence of a species are those that would 
appreciably reduce the likelihood of the species' survival and 
recovery. Actions likely to ``destroy or adversely modify'' critical 
habitat are those that would appreciably reduce the value of critical 
habitat for the survival and recovery of the listed species.
    Common to both definitions is an appreciable detrimental effect on 
the recovery of a listed species. Given the similarity of these 
definitions, actions likely to destroy or adversely modify critical 
habitat would almost always result in jeopardy to the species 
concerned, particularly when the species is present in the area of the 
proposed action. When the species is present in an area, designation of 
critical habitat for vernal pool crustaceans or vernal pool plants is 
not likely to result in regulatory requirements above those already in 
place due to the presence of the listed species. When the species is 
not present in an area, designation of critical habitat for vernal pool 
crustaceans or vernal pool plants may result in an additional 
regulatory burden when a Federal nexus exists.
    Section 4(b)(8) of the Act requires us to evaluate briefly and 
describe, in any proposed or final regulation that designates critical 
habitat, those activities involving a Federal action that may adversely 
modify such habitat or that may be affected by such designation. 
Activities that may destroy or adversely modify critical habitat would 
be those that alter the primary constituent elements to the extent that 
the value of critical habitat for the conservation of vernal pool 
crustaceans or vernal pool plants is appreciably reduced. We note that 
such activities may also jeopardize the continued existence of the 
species.
    Activities that, when carried out, funded, or authorized by a 
Federal agency may directly or indirectly destroy or adversely modify 
critical habitat for vernal pool crustaceans or vernal pool plants 
include, but are not limited to--
    (1) Any activity, including the regulation of activities by the 
Corps under section 404 of the Clean Water Act or activities carried 
out by or authorized by the EPA, that could alter the suitability of 
the watershed or water quality or quantity to support vernal pool 
crustaceans or vernal pool plants, or any activity that adversely 
affects the natural hydrologic function of the vernal pool system and/
or ephemeral pond or depression;
    (2) Road construction and maintenance, right-of-way designation, 
and regulation of agricultural activities, or any activity funded or 
carried out by

[[Page 59966]]

the Department of Transportation or Department of Agriculture that 
results in discharge of dredged or fill material, excavation, or 
mechanized land clearing of ephemeral and/or vernal pool basins;
    (3) Sale or exchange of lands by a Federal agency to a non-Federal 
entity which could foreseeably impact the primary constituent elements 
of critical habitat;
    (4) Regulation, relicensing, and operation of damming or other 
water impoundments by the BOR, Corps, or Federal Energy Regulatory 
Commission (FERC) that inundate critical habitat for vernal pool 
crustaceans;
    (5) Regulation by the Federal Aviation Administration (FAA) of 
airport improvement or maintenance activities that could foreseeably 
impact the primary constituent elements of critical habitat;
    (6) Licensing of construction of communication sites by the Federal 
Communications Commission (FCC) on lands containing critical habitat;
    (7) Funding of construction or development activities by the 
Department of Housing and Urban Development (HUD) or other agencies 
that destroy, fragment, or degrade suitable critical habitat;
    (8) Military training and maneuvers on applicable DOD lands which 
could foreseeably impact the primary constituent elements of critical 
habitat;
    (9) Signing of contracts to deliver water by the BOR in situations 
where those deliveries could foreseeably impact the primary constituent 
elements of critical habitat; and
    (10) Promulgation of a land use plan by a Federal agency such as 
the BLM, USFS, or DOD that may alter management practices for critical 
habitat.
    If you have questions regarding whether specific activities will 
constitute adverse modification of critical habitat in California, 
contact the Field Supervisor, Sacramento Fish and Wildlife Office (see 
ADDRESSES section). If the critical habitat occurs in Oregon, contact 
the Field Supervisor, Oregon Fish and Wildlife Office, 2600 S.E. 98th 
Avenue, Portland, OR 97266. Requests for copies of the regulations on 
listed wildlife, and inquiries about prohibitions and permits may be 
addressed to the U.S. Fish and Wildlife Service, Branch of Endangered 
Species, 911 N.E. 11th Ave, Portland, OR 97232 (telephone 503/231-2063; 
facsimile 503/231-6243).

Section 3(5)(A) Special Management Considerations

    Section 3(5)(A) of the Act defines critical habitat to be (among 
other things) areas within the current range of the species ``which may 
require special management considerations''. Accordingly, areas which 
will not require such special considerations are not critical habitat. 
For areas in the current range of the species, we first determine 
whether the area contains the physical and biological features 
essential to the conservation of the species and then determine whether 
the area has or needs special management or protection. Additional 
special management is not required if adequate management or protection 
is already in place. Adequate special management or protection is 
provided by a legally operative plan or agreement that addresses the 
maintenance and improvement of the primary constituent elements 
important to the species, and manages for the long-term conservation of 
the species. We use the following three criteria to determine if a plan 
provides adequate special management or protection: (1) A current plan 
or agreement must be complete and provide sufficient conservation 
benefit to the species, (2) the plan or agreement must provide 
assurances that the conservation management strategies will be 
implemented, and (3) the plan or agreement must provide assurances that 
the conservation management strategies will be effective, i.e., provide 
for periodic monitoring and revisions as necessary. If all of these 
criteria are met, then the lands covered under the plan would no longer 
meet the definition of critical habitat.
    The Sikes Act Improvements Act of 1997 (Sikes Act) requires each 
military installation that includes land and water suitable for the 
conservation and management of natural resources to complete, by 
November 17, 2001, an Integrated Natural Resources Management Plan 
(INRMP). An INRMP integrates implementation of the military mission of 
the installation with stewardship of the natural resources found there. 
Each INRMP includes an assessment of the ecological needs on the 
installation, including needs to provide for the conservation of listed 
species; a statement of goals and priorities; a detailed description of 
management actions to be implemented to provide for these ecological 
needs; and a monitoring and adaptive management plan. We consult with 
the military on the development and implementation of INRMPs for 
installations with listed species. We believe military bases that have 
completed and approved INRMPs that address the needs of the species 
generally do not meet the definition of critical habitat discussed 
above, as they require no additional special management or protection.
    We evaluated the status of INRMPs on DOD lands that were within the 
proposed critical habitat to determine whether any INRMPs met the 
special management criteria. To date, no DOD installation has completed 
a final INRMP that provides for sufficient conservation management and 
protection for the vernal pool crustaceans and plants. All DOD lands 
that contain the physical and biological features essential for the 
conservation of one of the vernal pool species have been included in 
the proposed designation of critical habitat for that species. Although 
no INRMPs for the vernal pool crustaceans and plants are currently in 
place on DOD lands within the proposed critical habitat, we will 
continue to work with the military bases to develop INRMPs to meet the 
special management criteria to preclude the final designation of 
critical habitat on their lands.

Exclusions Under Section 4(b)(2)

    Subsection 4(b)(2) of the Act allows us to exclude from critical 
habitat designation areas where the benefits of exclusion outweigh the 
benefits of designation, provided the exclusion will not result in the 
extinction of the species. However, prior to excluding these areas from 
critical habitat, we believe that it is best to fully and specifically 
describe the areas in the proposed designation, discuss our intent and 
rationale as to why we believe the areas should be excluded from 
designated critical habitat, and solicit public comment on the 
exclusion of these areas.
    We believe the proposed Skunk Hollow critical habitat (Unit 35) in 
Riverside County may warrant exclusion from the final designation of 
critical habitat under section 4(b)(2) of the Act based on the special 
management considerations and protections afforded the vernal pool 
habitat through several approved and legally operative HCPs. We believe 
that in most instances the benefits of excluding legally operative HCPs 
from the critical habitat designations will outweigh the benefits of 
including them. The following represents our rationale for proposing to 
exclude the Skunk Hollow critical habitat unit (Unit 35) from the final 
designated critical habitat.
(1) Benefits of Exclusion
    The benefits of excluding HCPs include relieving landowners, 
communities and counties of any

[[Page 59967]]

additional regulatory burden that might be imposed by critical habitat. 
This benefit is particularly compelling given the past representations 
on the part of the Service that once an HCP is negotiated and approved 
by us after public comment, activities consistent with the plan will 
satisfy the requirements of the Endangered Species Act. Many HCPs, 
particularly large regional HCPs, take many years to develop and, upon 
completion, become regional conservation plans that are consistent with 
the recovery of covered species. Imposing an additional regulatory 
review after HCP completion may jeopardize conservation efforts and 
partnerships in many areas and could be viewed as a disincentive to 
those developing HCPs. Excluding HCPs provides the Service an 
opportunity to streamline regulatory compliance, and provides 
regulatory certainty for HCP participants.
    Another critical benefit of excluding HCPs is that it would 
encourage the continued development of partnerships with HCP 
participants, including states, local governments, conservation 
organizations, and private landowners, that together can implement 
conservation actions we would be unable to accomplish. By excluding 
areas covered by HCPs from critical habitat designation, we clearly 
maintain our commitments, preserve these partnerships, and, we believe, 
set the stage for more effective conservation actions in the future.
(2) Benefits of Inclusion
    The benefits of including HCPs in critical habitat are normally 
small. The principal benefit of any designated critical habitat is that 
activities in such habitat that may affect it require consultation 
under section 7 of the Act. Such consultation would ensure that 
adequate protection is provided to avoid adverse modification of 
critical habitat. Where HCPs are in place, our experience indicates 
that this benefit is small or non-existent. Currently approved and 
permitted HCPs are already designed to ensure the long-term survival of 
covered species within the plan area. Where we have an approved HCP, 
lands that we ordinarily would define as critical habitat for covered 
species will normally be protected in reserves and other conservation 
lands by the terms of the HCPs and their Implementing Agreements. These 
HCPs and Implementing Agreements include management measures and 
protections for conservation lands designed to protect, restore, and 
enhance their value as habitat for covered species.
    In addition, an HCP application must itself be consulted upon. 
While this consultation will not look specifically at the issue of 
adverse modification of critical habitat, unless critical habitat has 
already been designated within the proposed plan area, it will look at 
the very similar concept of jeopardy to the listed species in the plan 
area. Because HCPs, particularly large regional HCPs, address land use 
within the plan boundaries, habitat issues within the plan boundaries 
will have been thoroughly addressed in the HCP and through the 
consultation on the HCP. Our experience is also that, under most 
circumstances, consultations under the jeopardy standard will reach the 
same result as consultations under the adverse modification standard. 
Implementing regulations (50 CFR 402.02 ) define ``jeopardize the 
continued existence of'' and ``destruction or adverse modification of'' 
in virtually identical terms. ``Jeopardize the continued existence of'' 
means to engage in an action ``that reasonably would be expected, 
directly or indirectly, to reduce appreciably the likelihood of both 
the survival and recovery of a listed species.'' Destruction or adverse 
modification means an ``alteration that appreciably diminishes the 
value of critical habitat for both the survival and recovery of a 
listed species.'' Common to both definitions is an appreciable 
detrimental effect on both survival and recovery of a listed species, 
in the case of critical habitat, by reducing the value of the habitat 
so designated. Thus, actions satisfying the standard for adverse 
modification are nearly always found to also jeopardize the species 
concerned, and the existence of a critical habitat designation does not 
materially affect the outcome of consultation. Additional measures to 
protect the habitat from adverse modification are not likely to be 
required.
    Further, HCPs typically provide for greater conservation benefits 
to a covered species than section 7 consultations because HCPs assure 
the long-term protection and management of a covered species and its 
habitat, and funding for such management through the standards found in 
the 5 Point Policy for HCPs (64 FR 35242) and the HCP No Surprises 
regulation (63 FR 8859). Such assurances are typically not provided by 
section 7 consultations which, in contrast to HCPs, often do not commit 
the project proponent to long-term special management or protections. 
Thus, a consultation typically does not accord the lands it covers the 
extensive benefits an HCP provides. The development and implementation 
of HCPs provide other important conservation benefits, including the 
development of biological information to guide conservation efforts and 
assist in species recovery, and the creation of innovative solutions to 
conserve species while allowing for development. The education benefits 
of critical habitat, including informing the public of areas that are 
important for long-term survival and conservation of the species, are 
essentially the same as those that would occur from the public notice 
and comment procedures required to establish an HCP, as well as the 
public participation that occurs in the development of many regional 
HCPs. For these reasons, then, we believe, that designation of critical 
habitat has little benefit in areas covered by HCPs, provided that the 
HCP and its associated Implementing Agreement are legally operative, 
and that the HCP specifically and adequately covers the species for 
which critical habitat is being designated.
    We have reviewed and evaluated HCPs currently approved and being 
properly and legally implemented within the areas being proposed for 
critical habitat for the vernal pool crustaceans and plants. Based on 
this evaluation, we find that the benefits of exclusion outweigh the 
benefits of designating the Skunk Hollow vernal pool (Unit 35) as 
critical habitat. The Skunk Hollow vernal pool basin consists of a 
single, large vernal pool and its essential associated watershed in 
western Riverside County. Several federally listed species have been 
documented from the Skunk Hollow vernal pool basin. These include the 
threatened vernal pool fairy shrimp (Simovich in litt 2001), the 
endangered Riverside fairy shrimp (Streptocephalus woottoni) (Service 
2001), the threatened spreading navarretia (Navarretia fossalis), and 
the endangered California Orcutt grass (Orcuttia californica) (Service 
1998). The vernal pool complex and watershed is currently protected as 
part of a reserve established within an approved mitigation bank in the 
Rancho Bella Vista HCP area and as part of the conservation measures 
contained in the Assessment District 161 Subregional HCP. While neither 
HCP include vernal pool fairy shrimp as a covered species, both HCPs 
provide protection for the vernal pool complex and its associated 
watershed in perpetuity. Further, the HCPs address the endangered 
Riverside fairy shrimp as a covered species. We believe that the 
management and protections afforded the vernal pool complex and the 
Riverside fairy shrimp

[[Page 59968]]

are adequate for the long-term conservation of this complex and this 
species, and to preserve the partnerships that we have developed with 
the local jurisdiction and project proponents in the development of 
these HCPs, we excluded the Skunk Hollow vernal pool complex from 
critical habitat for the Riverside fairy shrimp. We did not and still 
do not believe that this exclusion from critical habitat will result in 
the extinction of this Riverside fairy shrimp.
    Even though the two HCPs do not have vernal pool fairy shrimp 
listed as a covered species, we believe that the protections and 
management afforded the Skunk Hollow vernal pool complex and the other 
listed vernal pool species through the terms and conditions of those 
HCPs are adequate to ensure the long-term conservation of vernal pool 
fairy shrimp as well. Therefore, as with the Riverside fairy shrimp, we 
believe that the benefits of the exclusion of the Skunk Hollow vernal 
pool complex from critical habitat for vernal pool fairy shrimp 
outweighs the benefit of its inclusion. Additionally, we do not believe 
that this exclusion would result in the extinction of vernal pool fairy 
shrimp.
    Several HCP efforts are now under way that will address the 
conservation needs of the vernal pool crustaceans and plants in areas 
we propose as critical habitat. We have worked and continue to work 
closely with the HCP proponents to adequately address the conservation 
needs of these species within the boundaries of the HCPs. In the event 
that future HCPs, covering any of the vernal pool crustaceans or plants 
are developed within the boundaries of designated critical habitat, we 
will work with applicants to ensure that the HCPs provide for 
protection and management of habitat areas essential for the 
conservation of those species by either directing development and 
habitat modification to nonessential areas or appropriately modifying 
activities within essential habitat areas so that such activities will 
not destroy or adversely modify the primary constituent elements. The 
HCP development process provides an opportunity for more intensive data 
collection and analysis regarding the use of particular habitat areas 
by vernal pool crustaceans and plants. The process also enables us to 
conduct detailed evaluations of the importance of such lands to the 
long-term survival of these species in the context of constructing a 
biologically configured system of interlinked habitat blocks. We fully 
expect that HCPs undertaken by local jurisdictions (e.g., counties, 
cities) and other parties will identify, protect, and provide 
appropriate management for those specific lands within the boundaries 
of the plans that are essential for the long-term conservation of the 
species. We believe and fully expect that our analyses of these 
proposed HCPs and proposed permits under section 7 of the Act will show 
that covered activities carried out in accordance with the provisions 
of the HCPs and biological opinions will not result in destruction or 
adverse modification of critical habitat. We will provide technical 
assistance and work closely with applicants with respect to HCPs 
currently under development and future HCPs to identify lands essential 
for the long-term conservation of the vernal pool crustaceans and 
plants and appropriate management for those lands. The minimization and 
mitigation measures provided under these HCPs are expected to protect 
the essential habitat lands proposed as critical habitat in this rule. 
If an HCP that addresses any vernal pool crustacean or plant as a 
covered species is ultimately approved, we will reassess the critical 
habitat boundaries in light of the HCP. We intend to undertake this 
review when the HCP is approved, but funding and priority constraints 
may influence the timing of such a review. Should additional 
information become available that changes our analysis of the benefits 
of excluding any of these (or other) areas compared to the benefits of 
including them in the critical habitat designation, we may revise this 
proposed designation accordingly. Similarly, if new information 
indicates any areas we are proposing now should not be included in the 
critical habitat designation because they no longer meet the definition 
of critical habitat, we may revise this proposed critical habitat 
designation.

Economic Analysis

    Section 4(b)(2) of the Act requires us to designate critical 
habitat on the basis of the best scientific and commercial data 
available, and to consider the economic and other relevant impacts of 
designating a particular area as critical habitat. We may exclude areas 
from critical habitat upon a determination that the benefits of such 
exclusions outweigh the benefits of specifying such areas as critical 
habitat. We cannot exclude such areas from critical habitat when such 
exclusion will result in the extinction of the species. We will conduct 
an analysis of the economic impacts of designating these areas as 
critical habitat prior to a final determination. When completed, we 
will announce the availability of the draft economic analysis with a 
notice in the Federal Register, and we will open a public comment 
period on the draft economic analysis and re-open the comment period on 
the proposed rule at that time.

Public Comments Solicited

    We intend that any final action resulting from this proposal will 
be as accurate and effective as possible. Therefore, we solicit 
comments or suggestions from the public, other concerned governmental 
agencies, the scientific community, industry, or any other interested 
party concerning this proposed rule. We particularly seek comments 
concerning:
    (1) The reasons why any habitat should or should not be determined 
to be critical habitat as provided by section 4 of the Act, including 
whether the benefits of designation will outweigh any threats to the 
species due to designation and whether areas under consideration 
require additional special management;
    (2) Specific information on the amount and distribution of any of 
the vernal pool crustaceans or vernal pool plants and what habitat is 
essential to the conservation of these species and why;
    (3) Land use designations and current or planned activities in the 
subject areas and their possible impacts on proposed critical habitat; 
in particular, in Oregon, we seek information related to potential of 
selected parcels to contribute to the species recovery, considering 
their zoning, adjacent land uses, watershed integrity, and potential 
for edge effects (related to shape of parcel);
    (4) Any foreseeable economic or other impacts resulting from the 
proposed designation of critical habitat, in particular, any impacts on 
small entities or families;
    (5) Economic and other values associated with designating critical 
habitat for vernal pool crustaceans and vernal pool plants such as 
those derived from non-consumptive uses (e.g., hiking, camping, bird-
watching, enhanced watershed protection, improved air quality, 
increased soil retention, ``existence values,'' and reductions in 
administrative costs);
    (6) Whether any areas should be excluded pursuant to section 
4(b)(2); and
    (7) Whether our approach to critical habitat designation could be 
improved or modified in any way to provide for greater public 
participation and understanding, or to assist us in accommodating 
public concern and comments.

[[Page 59969]]

    If you wish to comment on this proposed rule, you may submit your 
comments and materials by any one of several methods (see ADDRESSES). 
Please submit electronic mail comments as an ASCII file and avoid the 
use of special characters and any form of encryption. Please also 
include ``Attn: [RIN number]'' and your name and return address in your 
electronic message. Please note that the electronic address fw1--
vernalpool@fws.gov will be closed out at the termination of the public 
comment period. If you do not receive a confirmation from the system 
that we have received your electronic message, contact us directly by 
calling our Sacramento Fish and Wildlife Office at phone number 916/
414-6600.
    Our practice is to make comments, including names and home 
addresses of respondents, available for public review during regular 
business hours. Individual respondents may request that we withhold 
their home address from the rulemaking record, which we will honor to 
the extent allowable by law. In some circumstances, we would withhold 
from the rulemaking record a respondent's identity, as allowable by 
law. If you wish us to withhold your name and/or address, you must 
state this prominently at the beginning of your comment. However, we 
will not consider anonymous comments. To the extent consistent with 
applicable law, we will make all submissions from organizations or 
businesses, and from individuals identifying themselves as 
representatives or officials of organizations or businesses, available 
for public inspection in their entirety. Comments and materials 
received will be made available for public inspection, by appointment, 
during normal business hours at the above address.

Peer Review

    In accordance with our policy published on July 1, 1994 (59 FR 
34270), we will solicit the expert opinions of at least three 
appropriate and independent specialists regarding this proposed rule. 
The purpose of such review is to ensure listing decisions are based on 
scientifically sound data, assumptions, and analyses. We will send 
these peer reviewers copies of this proposed rule immediately following 
publication in the Federal Register. We will invite these peer 
reviewers to comment, during the public comment period, on the specific 
assumptions and conclusions regarding the proposed designation of 
critical habitat.
    We will consider all comments and information received during the 
120-day public comment period on this proposed rule during preparation 
of a final rulemaking. Accordingly, the final decision may differ from 
this proposal.

Public Hearings

    The Act provides for one or more public hearings on this proposal, 
if requested. Requests for public hearings must be made at least 15 
days prior to the close of the public comment period. We will schedule 
public hearings on this proposal, if any are requested, and announce 
the dates, times, and places of those hearings in the Federal Register 
and local newspapers at least 15 days before the first hearing is held.

Clarity of the Rule

    Executive Order 12866 requires each agency to write regulations and 
notices that are easy to understand. We invite your comments on how to 
make this proposed rule easier to understand, including answers to 
questions such as the following: (1) Are the requirements in the 
proposed rule clearly stated? (2) Does the proposed rule contain 
technical language or jargon that interferes with the clarity? (3) Does 
the format of the proposed rule (grouping and order of sections, use of 
headings, paragraphing, etc.) aid or reduce its clarity? (4) Is the 
description of the proposed rule in the SUPPLEMENTARY INFORMATION 
section of the preamble helpful in understanding the proposed rule? 
What else could we do to make the proposed rule easier to understand?
    Send a copy of any comments that concern how we could make this 
rule easier to understand to: Office of Regulatory Affairs, Department 
of Interior, Room 7229, 1849 C Street, NW., Washington, DC 20240. You 
may e-mail your comments to this address: Exsec@ios.doi.gov.

Required Determinations

Regulatory Planning and Review

    In accordance with Executive Order 12866, this document is a 
significant rule and was reviewed by the Office of Management and 
Budget (OMB). The Service is preparing a draft economic analysis of 
this proposed action. The Service will use this analysis to meet the 
requirement of section 4(b)(2) of the ESA to determine the economic 
consequences of designating the specific areas as critical habitat and 
excluding any area from critical habitat if it is determined that the 
benefits of such exclusion outweigh the benefits of specifying such 
areas as part of the critical habitat, unless failure to designate such 
area as critical habitat will lead to the extinction of any of the 
vernal pool species included in this rule. This analysis will be 
available for public comment before finalizing this designation. The 
availability of the draft economic analysis will be announced in the 
Federal Register.

Regulatory Flexibility Act (5 U.S.C. 601 et seq.)

    This discussion is based upon the information regarding potential 
economic impact that is available to the Service at this time. This 
assessment of economic effect may be modified prior to final rulemaking 
based upon development and review of the economic analysis being 
prepared pursuant to section 4(b)(2) of the ESA and E.O. 12866. This 
analysis is for the purposes of compliance with the Regulatory 
Flexibility Act and does not reflect the position of the Service on the 
type of economic analysis required by New Mexico Cattle Growers Assn. 
v. U.S. Fish & Wildlife Service 248 F.3d 1277 (10th Cir. 2001).
    Under the Regulatory Flexibility Act (5 U.S.C. 601 et seq., as 
amended by the Small Business Regulatory Enforcement Fairness Act 
(SBREFA) of 1996), whenever an agency is required to publish a notice 
of rulemaking for any proposed or final rule, it must prepare and make 
available for public comment a regulatory flexibility analysis that 
describes the effect of the rule on small entities (i.e., small 
businesses, small organizations, and small government jurisdictions). 
However, no regulatory flexibility analysis is required if the head of 
the agency certifies the rule will not have a significant economic 
impact on a substantial number of small entities. SBREFA amended the 
Regulatory Flexibility Act to require Federal agencies to provide a 
statement of the factual basis for certifying that a rule will not have 
a significant economic impact on a substantial number of small 
entities. SBREFA also amended the RFA to require a certification 
statement. We are hereby certifying that this proposed rule will not 
have a significant economic impact on a substantial number of small 
entities. The following discussion explains our rationale for making 
this assertion.
    According to the Small Business Administration (http://www.sba.gov/
size/), small entities include small organizations, such as independent 
non-profit organizations, and small governmental jurisdictions, 
including school boards and city and town governments that serve fewer 
than 50,000 residents, as well as small businesses. Small businesses 
include manufacturing and mining concerns with fewer than 500 
employees, wholesale trade entities with fewer than 100 employees, 
retail and service

[[Page 59970]]

businesses with less than $5 million in annual sales, general and heavy 
construction businesses with less than $27.5 million in annual 
business, special trade contractors doing less than $11.5 million in 
annual business, and agricultural businesses with annual sales less 
than $750,000. To determine if potential economic impacts to these 
small entities are significant, we consider the types of activities 
that might trigger regulatory impacts under this rule as well as the 
types of project modifications that may result. In general, the term 
``significant economic impact'' is meant to apply to a typical small 
business firm's business operations.
    In determining whether this rule could ``significantly affect a 
substantial number of small entities'', the economic analysis first 
determines whether critical habitat could potentially affect a 
``substantial number'' of small entities in counties supporting 
critical habitat areas. While SBREFA does not explicitly define 
``substantial number,'' the Small Business Administration, as well as 
other Federal agencies, have interpreted this to represent an impact on 
20 percent or greater of the number of small entities in any industry. 
In some circumstances, especially with critical habitat designations of 
limited extent, we may aggregate across all industries and consider 
whether the total number of small entities affected is substantial. In 
estimating the numbers of small entities potentially affected, we also 
considered whether their activities have any Federal involvement. 
Designation of critical habitat only affects activities conducted, 
funded, or permitted by Federal agencies. Some kinds of activities are 
unlikely to have any Federal involvement and so will not be affected by 
critical habitat designation.
    Designation of critical habitat only affects activities conducted, 
funded, or permitted by Federal agencies; non-Federal activities are 
not affected by the designation. In areas where the species are 
present, Federal agencies are already required to consult with us under 
section 7 of the Act on activities that they fund, permit, or implement 
that may affect vernal pool crustaceans and plants for whom designation 
of critical habitat is proposed. If this critical habitat designation 
is finalized, Federal agencies also must ensure, also through 
consultation with us, that their activities do not destroy or adversely 
modify designated critical habitat. However, for the reasons discussed 
above, we do not believe this will result in any additional regulatory 
burden on Federal agencies or their applicants.
    In areas that we are proposing to designate as critical habitat 
where occupancy status is currently unknown, but is presumed to be 
likely, a potential does exist that designation as critical habitat 
would trigger additional Federal review for activities having a Federal 
nexus (e.g., funded, permitted, authorized, etc.). We base this 
determination upon the present and ongoing regulatory framework in 
which the Corps consults with us under section 7 of the Act in the vast 
majority of cases where their actions may affect vernal pools. These 
section 7 consultations are currently precipitated by either the known 
or presumed occupancy of one or more of the vernal pool crustaceans or 
plants addressed in this rule. In those rare circumstances where the 
Corps does not consult with us under section 7 of the Act, we believe 
that an HCP would still be required, based on known or a high 
likelihood of occupancy. Any change or deviation in the present 
regulatory climate is purely speculative at this time. Therefore, we do 
not expect the final designation of critical habitat as proposed in 
this rule to substantially increase the regulatory or economic burden 
on project proponents beyond that which is presently required through 
the likely presence of one or more listed species, where the necessary 
primary constituent elements are present. As a result of this minimal 
increase in the regulatory or economic burdens on any project 
proponents, we do not believe that this proposed designation of 
critical habitat for the vernal pool crustaceans and plants will cause 
a significant economic impact on a substantial number of small 
entities.
    We note that for actions on non-Federal property that do not have a 
Federal connection (such as funding or authorization), the current 
restrictions concerning take of the species remain in effect, and that 
this proposed rule will place no additional restrictions on such 
activities.
    Therefore, based on the above evaluation, we are certifying that 
this proposed designation of critical habitat for the vernal pool 
crustaceans and plants is not expected to have a significant economic 
impact on a substantial number of small entities, and that an initial 
regulatory flexibility analysis is not required. However, should the 
economic analysis of this proposed rule indicate that there may be 
significant economic impacts on a substantial number of small entities, 
we will revisit this determination.

Executive Order 13211

    On May 18, 2001, the President issued an Executive Order (EO 13211) 
on regulations that significantly affect energy supply, distribution, 
and use. Executive Order 13211 requires agencies to prepare Statements 
of Energy Effects when undertaking certain actions. Although this rule 
is a significant regulatory action under Executive Order 12866, it is 
not expected to significantly affect energy supplies, distribution, or 
use. Therefore, this action is not a significant energy action and no 
Statement of Energy Effects is required.

Unfunded Mandates Reform Act (2 U.S.C. 1501 et seq.)

    The Service will use the economic analysis to evaluate consistency 
with the Unfunded Mandates Reform Act (2 U.S.C. 1501 et seq.).

Takings

    In accordance with Executive Order 12630 (``Government Actions and 
Interference with Constitutionally Protected Private Property 
Rights''), we have analyzed the potential takings implications of 
designating critical habitat for these 15 vernal pool species in a 
preliminary takings implications assessment. This preliminary 
assessment concludes that this proposed rule does not pose significant 
takings implications. However, we have not yet completed the economic 
analysis for this proposed rule. Once the economic analysis is 
available, we will review and revise this preliminary assessment as 
warranted.

Federalism

    In accordance with Executive Order 13132, the rule does not have 
significant Federalism effects. A Federalism assessment is not 
required. In keeping with Department of the Interior policy, we 
requested information from, and coordinated development of this 
critical habitat proposal with appropriate State resource agencies in 
California. We will continue to coordinate any future designation of 
critical habitat for the vernal pool crustaceans and vernal pool plants 
with the appropriate State agencies. The designation of critical 
habitat in areas currently occupied by the vernal pool crustaceans and 
vernal pool plants imposes no additional restrictions to those 
currently in place and, therefore, has little incremental impact on 
State and local governments and their activities. The designation may 
have some benefit to these governments in that the areas essential to 
the conservation of the species are more clearly defined, and the 
primary constituent elements of the habitat

[[Page 59971]]

necessary to the survival of the species are specifically identified. 
While making this definition and identification does not alter where 
and what federally sponsored activities may occur, it may assist these 
local governments in long range planning rather than waiting for case 
by case section 7 consultations to occur.

Civil Justice Reform

    In accordance with Executive Order 12988, the Office of the 
Solicitor has determined that the rule does not unduly burden the 
judicial system and meets the requirements of sections 3(a) and 3(b)(2) 
of the Order. We designate critical habitat in accordance with the 
provisions of the Act. The rule uses standard property descriptions and 
identifies the primary constituent elements within the designated areas 
to assist the public in understanding the habitat needs of the vernal 
pool crustaceans or vernal pool plants.

Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.)

    This rule does not contain any new collections of information that 
require approval by OMB under the Paperwork Reduction Act. This rule 
will not impose new record keeping or reporting requirements on State 
or local governments, individuals, businesses, or organizations. An 
agency may not conduct or sponsor, and a person is not required to 
respond to a collection of information unless it displays a currently 
valid OMB control number.

National Environmental Policy Act

    We have determined that an Environmental Assessment or an 
Environmental Impact Statement as defined by the National Environmental 
Policy Act of 1969 need not be prepared in connection with regulations 
adopted pursuant to section 4(a) of the Act. A notice outlining our 
reason for this determination was published in the Federal Register on 
October 25, 1983 (48 FR 49244). This proposed rule does not constitute 
a major Federal action significantly affecting the quality of the human 
government.

Government to Government Relationship With Tribes

    In accordance with the President's memorandum of April 29, 1994, 
``Government-to-Government Relations with Native American Tribal 
Governments `` (59 FR 22951), E.O. 13175, and Department of the 
Interior's manual at 512 DM 2, we readily acknowledge our 
responsibility to communicate meaningfully with recognized Federal 
Tribes on a government to government basis. We have determined that 
there are no Tribal lands essential for the conservation of the vernal 
pool crustaceans and plants addressed in this proposed rule because 
they do not support populations or suitable habitat. Therefore, 
critical habitat for these species has not been proposed for 
designation on Tribal lands.

References Cited

    A complete list of all references cited herein, as well as others, 
is available upon request from the Sacramento Fish and Wildlife Office 
(see ADDRESSES section).

Authors

    The primary authors of this notice are the staff of the Sacramento 
Fish and Wildlife Office (see ADDRESSES section).

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Reporting and 
recordkeeping requirements, Transportation.

Proposed Regulation Promulgation

    Accordingly, we propose to amend part 17, subchapter B of chapter 
I, title 50 of the code of Federal Regulations as set forth below:

PART 17--[AMENDED]

    1. The authority citation for part 17 continues to read as follows:

    Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C. 
4201-4245; Pub. L. 99-625, 100 Stat. 3500; unless otherwise noted.

    2. In Sec.  17.11(h) revise the entry for ``Fairy shrimp, 
Conservancy,'' ``Fairy shrimp, longhorn,'' ``Fairy shrimp, vernal 
pool,'' and ``Tadpole shrimp, vernal pool'' under ``CRUSTACEANS'' to 
read as follows:


Sec.  17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------
                      Species                                                Vertebrate
----------------------------------------------------                      population where                                                     Special
                                                       Historic range       endangered or        Status     When listed   Critical habitat      rules
          Common name              Scientific name                           threatened
--------------------------------------------------------------------------------------------------------------------------------------------------------

                                                                      * * * * * * *
          Crustaceans

                                                                      * * * * * * *
Fairy shrimp, Conservancy......  Branchinecta        U.S.A. (CA).......  Entire............  E                      552  17.95(h)..........           NA
                                  conservatio.
Fairy shrimp, longhorn.........  Branchinecta        U.S.A. (CA).......  Entire............  E                      552  17.95(h)..........           NA
                                  longiantenna.

                                                                      * * * * * * *
Fairy shrimp, vernal pool......  Branchinecta        U.S.A. (CA, OR)...  Entire............  T                      552  17.95(h)..........           NA
                                  lynchi.
Tadpole shrimp, vernal pool....  Lepidurus packardi  U.S.A. (CA).......  Entire............  E                      552  17.95(h)..........           NA

                                                                      * * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------

    3. In Sec.  17.12(h) revise the entry for Castilleja campestris 
ssp. succulenta (succulent (or fleshy) owl's-clover), Chamaesyce 
hooveri (Hoover's spurge), Lasthenia conjugens (Contra Costa 
goldfields), Limnanthes floccosa ssp. californica (Butte County 
meadowfoam), Neostapfia colusana (Colusa grass), Orcuttia inaequalis 
(San Joaquin Valley Orcutt grass), Orcuttia pilosa (hairy Orcutt 
grass), Orcuttia tenuis (slender Orcutt grass), Orcuttia viscida

[[Page 59972]]

(Sacramento Orcutt grass), Tuctoria greenei (Greene's tuctoria), and 
Tuctoria mucronata (Solano grass) under ``FLOWERING PLANTS'' to read as 
follows--


Sec.  17.12  Endangered and threatened plants.

* * * * *
    (h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------
                      Species
----------------------------------------------------   Historic range          Family            Status     When listed   Critical habitat     Special
        Scientific name              Common name                                                                                                rules
--------------------------------------------------------------------------------------------------------------------------------------------------------
        Flowering Plants

                                                                      * * * * * * *
Castilleja campestris ssp.       Fleshy owl's        U.S.A. (CA).......  Scrophulariaceae..  T                      611  17.96(a)..........           NA
 succulenta.                      clover.

                                                                      * * * * * * *
Chamaesyce hooveri.............  Hoover's spurge...  U.S.A. (CA).......  Euphorbiaceae.....  T                      611  17.96(a)..........           NA

                                                                      * * * * * * *
Lasthenia conjugens............  Contra Costa        U.S.A. (CA).......  Asteraceae........  E                      619  17.96(a)..........           NA
                                  goldfields.

                                                                      * * * * * * *
Limnanthes floccosa ssp.         Butte County        U.S.A. (CA).......  Limnanthaceae.....  E                      471  17.96(a)..........           NA
 californica.                     meadowfoam.

                                                                      * * * * * * *
Neostapfia colusana............  Colusa grass......  U.S.A. (CA).......  Poaceae...........  T                      611  17.96(a)..........           NA

                                                                      * * * * * * *
Orcuttia inaequalis............  San Joaquin Valley  U.S.A. (CA).......  Poaceae...........  T                      611  17.96(a)..........           NA
                                  [chyph]Orcutt
                                  grass.
Orcuttia pilosa................  Hairy Orcutt grass  U.S.A. (CA).......  Poaceae...........  E                      611  17.96(a)..........           NA
Orcuttia tenuis................  Slender Orcutt      U.S.A. (CA).......  Poaceae...........  T                      611  17.96(a)..........           NA
                                  grass.
Orcuttia viscida...............  Sacramento Orcutt   U.S.A. (CA).......  Poaceae...........  E                      611  17.96(a)..........           NA
                                  grass.
Tuctoria greenei...............  Greene's tuctoria.  U.S.A. (CA).......  Poaceae...........  E                      611  17.96(a)..........           NA

                                                                      * * * * * * *
Tuctoria mucronata.............  Solano grass......  U.S.A. (CA).......  Poaceae...........  E                       44  17.96(a)..........           NA

                                                                      * * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------

    4. In Sec.  17.95 add critical habitat for Conservancy fairy shrimp 
(Branchinecta conservatio), longhorn fairy shrimp (Branchinecta 
longiantenna), vernal pool fairy shrimp (Branchinecta lynchi), and 
vernal pool tadpole shrimp (Lepidurus packardi) under paragraph (h) in 
the same alphabetical order as this species occurs in Sec.  17.11(h), 
to read as follows:


Sec.  17.95  Critical habitat--fish and wildlife.

* * * * *
    (h) Crustaceans.
* * * * *
Conservancy fairy shrimp (Branchinecta conservatio)
    (1) Critical habitat units are depicted for Tehama, Butte, Glenn, 
Colusa, Solano, Stanislaus, Merced, Mariposa and Ventura counties, 
California, on the map below.
    (2) The primary constituent elements of critical habitat for 
Branchinecta conservatio are the habitat components that provide--
    (i) Vernal pools, swales, and other ephemeral wetlands and 
depressions of appropriate sizes and depths that typically become 
inundated during winter rains and hold water for sufficient lengths of 
time necessary for Conservancy fairy shrimp incubation, reproduction, 
dispersal, feeding, and sheltering, including but not limited to large, 
playa vernal pools often on basin rim landforms and alkaline soils, but 
which are dry during the summer and do not necessarily fill with water 
every year; and
    (ii) The geographic, topographic, and edaphic features that support 
aggregations or systems of hydrologically interconnected pools, swales, 
and other ephemeral wetlands and depressions within a matrix of 
surrounding uplands that together form hydrologically and ecologically 
functional units called vernal pool complexes. These features 
contribute to the filling and drying of the vernal pool, and maintain 
suitable periods of pool inundation, water quality, and soil moisture 
for vernal pool crustacean hatching, growth and reproduction, and 
dispersal, but not necessarily every year.
    (3) Existing man-made features and structures, such as buildings, 
roads, railroads, airports, runways, other paved areas, lawns, and 
other urban landscaped areas do not contain one or more of the primary 
constituent elements. Federal actions limited to those areas, 
therefore, would not trigger a consultation under section 7 of the Act 
unless they may affect the species and/or primary constituent elements 
in adjacent critical habitat.
    (4) Unit 1: Butte and Tehama Counties, California.
    (i) From USGS 1:24,000 quadrangle maps Acorn Hollow, Campbell 
Mound, Foster Island, Nord, Richardson Springs, Richardson Springs NW, 
and Vina, California, land bounded by the following UTM 10 NAD 83 
coordinates (E, N): 595500, 4408200; 594300, 4408200; 594100, 4408300; 
594000, 4408400; 593600, 4408500; 593400, 4408200; 592600, 4408200; 
592500, 4408700; 592100, 4408500; 592000, 4408700; 591400, 4408700; 
590700,

[[Page 59973]]

4408700; 590400, 4408300; 589900, 4408300; 589000, 4408600; 589000, 
4409300; 589100, 4409900; 588900, 4410200; 588200, 4410300; 588200, 
4411000; 587900, 4411400; 587900, 4412000; 587900, 4412400; 587600, 
4412700; 587600, 4413400; 584200, 4413400; 583100, 4413100; 582900, 
4413400; 582900, 4415900; 582000, 4418300; 581800, 4419200; 582000, 
4419500; 581400, 4420000; 581400, 4420400; 581800, 4420700; 581600, 
4421000; 583200, 4422600; 583500, 4423600; 585200, 4424500; 586000, 
4424500; 587500, 4426100; 588200, 4426500; 588600, 4429100; 588800, 
4430200; 589500, 4429500; 589500, 4428600; 591400, 4425800; 592600, 
4424100; 593400, 4422300; 594200, 4421100; 595900, 4417800; 595800, 
4417300; 595800, 4416600; 596100, 4416600; 596400, 4416800; 596600, 
4416800; 597100, 4416400; 597100, 4415600; 596800, 4415200; 597100, 
4415000; 597800, 4415500; 598100, 4415200; 597600, 4414600; 597600, 
4414400; 597300, 4413800; 597300, 4413300; 598200, 4413900; 598400, 
4413900; 598400, 4413600; 597400, 4411900; 597600, 4411900; 598300, 
4412700; 598500, 4413300; 598900, 4413300; 598900, 4411800; 599400, 
4411700; 599800, 4411700; 599800, 4411000; 597700, 4409400; 596200, 
4408600; 595900, 4408800; 595700, 4408800; returning to 595500, 
4408200.
    (5) Unit 2: Colusa and Glenn Counties, California.
    (i) From USGS 1:24,000 quadrangle maps Logandale, Maxwell, Moulton 
Weir, and Princeton, California, land bounded by the following UTM 10 
NAD 83 coordinates (E, N): 572900, 4357400; 571200, 4357400; 571200, 
4358200; 570400, 4358200; 570400, 4359000; 569600, 4359000; 569500, 
4360500; 569300, 4362200; 569500, 4363300; 569500, 4367200; 570000, 
4367200; 569900, 4368400; 570300, 4368400; 571000, 4367600; 571000, 
4367800; 570700, 4368500; 570900, 4368800; 571500, 4368800; 571900, 
4368300; 571900, 4367600; 572100, 4367600; 572400, 4368100; 572400, 
4368400; 572600, 4368900; 572800, 4368900; 573000, 4368100; 573400, 
4368000; 573800, 4367600; 574100, 4367300; 574400, 4367200; 574500, 
4366400; 574900, 4366400; 574900, 4365600; 574700, 4365500; 574400, 
4364100; 575200, 4363900; 575600, 4363600; 575100, 4362400; 575600, 
4361400; 575100, 4360700; 576000, 4359600; 575500, 4358900; 575700, 
4358300; 575900, 4357700; 575300, 4357800; 575000, 4357700; 574700, 
4357700; 573600, 4357800; 573500, 4358200; 572900, 4358200; returning 
to 572900, 4357400.
    (6) Unit 3: Solano County, California.
    (i) From USGS 1:24,000 quadrangle maps Birds Landing, Denverton, 
Dozier, and Elmira, California, land bounded by the following UTM 10 
NAD 83 coordinates (E, N): 596700, 4230400; 596200, 4230400; 595900, 
4230500; 595700, 4230600; 594500, 4231200; 593800, 4231200; 593600, 
4230500; 589300, 4230700; 589000, 4231200; 589100, 4231300; 589100, 
4231700; 588900, 4232300; 588900, 4233000; 590200, 4233600; 590500, 
4233700; 591000, 4233700; 590900, 4233200; 591100, 4233100; 591300, 
4233100; 592000, 4233700; 592500, 4233900; 593500, 4234200; 594800, 
4235500; 594900, 4235800; 595600, 4236300; 595600, 4236800; 596500, 
4237600; 596300, 4237700; 595500, 4237100; 595200, 4237700; 595200, 
4238200; 598800, 4238200; 598500, 4239100; 598000, 4239700; 598000, 
4241000; 598800, 4241000; 598800, 4240600; 600400, 4240600; 602800, 
4240600; 604300, 4239400; 605200, 4240600; 605300, 4239700; 605500, 
4239000; 605400, 4238300; 604500, 4238100; 604500, 4237500; 605200, 
4237200; 605700, 4235200; 605400, 4234900; 605000, 4233900; 604600, 
4233700; 604200, 4233300; 604100, 4232500; 603800, 4231500; 602300, 
4230800; 601400, 4230700; 600700, 4230600; 600400, 4230900; 600400, 
4231700; 601100, 4232300; 601200, 4233200; 598400, 4233200; 598200, 
4232100; 597800, 4231800; 597400, 4230900; returning to 596700, 
4230400.
    (7) Unit 4: Solano County, California.
    (i) From USGS 1:24,000 quadrangle maps Antioch North and Honker 
Bay, California, land bounded by the following UTM 10 NAD 83 
coordinates (E, N): 600900, 4215500; 599300, 4215500; 598400, 4216900; 
598316, 6875000, 4217900; 598400, 4217900; 598800, 4218100; 598800, 
4218600; 599000, 4219000; 599200, 4219300; 599400, 4219500; 600600, 
4216900; returning to 600900, 4215500.
    (8) Unit 5: Stanislaus County, California.
    (i) From USGS 1:24,000 quadrangle map Ripon, California, land 
bounded by the following UTM 10 NAD 83 coordinates (E, N): 660800, 
4167200; 660000, 4167200; 659500, 4168800; 661600, 4168800; 661600, 
4169400; 662400, 4169400; 662400, 4168300; 661600, 4168000; 661600, 
4168300; 660300, 4167800; 660600, 4167500; returning to 660800, 
4167200.
    (9) Unit 6: Mariposa and Merced Counties, California.
    (i) From USGS 1:24,000 quadrangle maps Atwater, Haystack Mtn., 
Illinois Hill, Indian Gulch, Le Grand, Merced, Merced Falls, Owens 
Reservoir, Plainsburg, Planada, Raynor Creek, Snelling, Winton, and 
Yosemite Lake, California, land bounded by the following UTM 10 NAD 83 
coordinates (E, N): 750200, 4121400; 747800, 4121400; 747800, 4121900; 
747500, 4122400; 747500, 4123900; 747000, 4124700; 746900, 4125100; 
743600, 4125000; 743600, 4127000; 742700, 4127000; 742600, 4126600; 
742300, 4126300; 741700, 4126300; 741200, 4126800; 741200, 4128600; 
740400, 4128600; 740400, 4130300; 739000, 4130300; 739000, 4130600; 
738400, 4131100; 737500, 4131200; 737800, 4131700; 737700, 4132600; 
737700, 4132900; 737100, 4132900; 737100, 4134200; 736700, 4134200; 
736100, 4133900; 735600, 4133300; 734700, 4133300; 734700, 4133700; 
734100, 4133900; 733100, 4133900; 733100, 4134600; 732700, 4134600; 
732600, 4135000; 732300, 4135500; 730300, 4135400; 729900, 4135700; 
729900, 4136500; 726500, 4136500; 726400, 4136100; 725900, 4136100; 
725900, 4135300; 725600, 4135100; 725500, 4135100; 725300, 4135500; 
725100, 4135400; 725000, 4135400; 725000, 4135600; 724800, 4135700; 
724600, 4135700; 724600, 4134700; 724200, 4134700; 724200, 4135500; 
723400, 4135500; 723400, 4135600; 722800, 4135600; 722800, 4135000; 
722600, 4135000; 722600, 4134700; 722500, 4134700; 722200, 4137900; 
722800, 4137900; 722800, 4139300; 721900, 4139300; 721900, 4140200; 
721000, 4140200; 721000, 4140900; 717800, 4140900; 717800, 4137700; 
717100, 4137700; 717000, 4138200; 714500, 4140900; 714100, 4141300; 
714100, 4142200; 713600, 4142400; 713200, 4143000; 713000, 4143900; 
713100, 4144300; 713700, 4144600; 714500, 4145300; 714500, 4145700; 
715800, 4145800; 717000, 4145800; 718000, 4145400; 718200, 4145900; 
718200, 4147600; 719700, 4148400; 720600, 4148600; 720600, 4149200; 
719600, 4149200; 719600, 4149800; 720300, 4149800; 721300, 4150700; 
721700, 4150700; 724400, 4153300; 725000, 4153500; 725500, 4154200; 
725800, 4154800; 727200, 4155900; 727800, 4155900; 728500, 4155600; 
730200, 4155600; 731600, 4155500; 732400, 4155400; 732600, 4155200; 
733200, 4154700; 734100, 4154900; 734600, 4154800; 735600, 4156000; 
735900, 4156000; 737100, 4155400; 737800, 4155000; 738200, 4154200; 
738300, 4153300; 739000, 4152800; 739100, 4152200; 740200, 4151800; 
740800, 4151500; 740800, 4150300; 741100, 4149900; 741700, 4149400; 
742100, 4148500; 742100, 4147100; 743400, 4146100; 744000, 4145600; 
744400,

[[Page 59974]]

4144600; 744300, 4143900; 743900, 4142700; 744000, 4142000; 744200, 
4141700; 745500, 4140300; 746100, 4139500; 746800, 4138500; 747700, 
4137700; 748500, 4135800; 748700, 4135100; 749500, 4134000; 750100, 
4132800; 750700, 4131700; 751600, 4130500; 752000, 4130200; 752800, 
4130100; 753300, 4130400; 753500, 4130400; 753900, 4130200; 754000, 
4129300; 753400, 4128400; 753900, 4127700; 754400, 4127700; 754600, 
4127400; 755300, 4128400; 755400, 4128400; 755600, 4127700; 756900, 
4126400; 757800, 4125800; 758400, 4126300; 758500, 4126300; 758600, 
4126000; 757900, 4125100; 757400, 4125100; 756500, 4123700; 753500, 
4122400; 750200, 4122400; returning to 750200, 4121400.
    (10) Unit 7: Merced County, California.
    (i) From USGS 1:24,000 quadrangle maps Arena, Atwater, Gustine, 
Ingomar, Los Banos, San Luis Ranch, Sandy Mush, Stevinson, and Turner 
Ranch, California, land bounded by the following UTM 10 NAD 83 
coordinates (E, N): 697300, 4104500; 696100, 4104500; 695700, 4105000; 
695700, 4106600; 694700, 4107900; 693500, 4107900; 693700, 4109100; 
692900, 4109100; 692900, 4109800; 693100, 4110200; 693800, 4110200; 
693800, 4111800; 692500, 4111800; 692400, 4110600; 691800, 4110600; 
691600, 4110200; 690800, 4110300; 690000, 4110300; 690000, 4111400; 
689700, 4111800; 689200, 4111800; 689200, 4111300; 688400, 4111300; 
688400, 4112100; 686700, 4112100; 686500, 4112900; 686500, 4113700; 
686000, 4113700; 686000, 4116100; 684500, 4116100; 684400, 4114200; 
682200, 4114200; 682100, 4113000; 681100, 4113000; 681100, 4111800; 
680600, 4111700; 679600, 4110900; 678800, 4110900; 678200, 4111800; 
678300, 4113600; 677900, 4114400; 679400, 4114400; 679400, 4115200; 
680000, 4115200; 680300, 4116000; 681800, 4116100; 682800, 4116600; 
683600, 4116500; 683600, 4117100; 681200, 4117100; 681000, 4124500; 
680800, 4124900; 679800, 4124900; 679800, 4125700; 680700, 4125700; 
680600, 4126400; 680300, 4126700; 680300, 4127200; 678900, 4127800; 
679000, 4129000; 679300, 4129200; 680100, 4129400; 679700, 4130700; 
679400, 4130200; 678600, 4130200; 678000, 4131200; 678500, 4132100; 
678800, 4132400; 679000, 4131800; 679200, 4131800; 680200, 4132200; 
680700, 4131700; 681600, 4132800; 681200, 4133100; 681200, 4133600; 
681600, 4134100; 681700, 4134200; 681900, 4134200; 682300, 4134000; 
682700, 4133800; 683400, 4133100; 683600, 4132600; 683600, 4132300; 
683100, 4131800; 683100, 4131500; 683400, 4131500; 684300, 4130400; 
684700, 4130000; 685500, 4130700; 686000, 4130700; 686200, 4130900; 
686400, 4130900; 688800, 4131400; 690300, 4131400; 690500, 4130600; 
691600, 4130600; 691600, 4130000; 692900, 4130000; 692800, 4131700; 
692400, 4131800; 692400, 4133500; 693000, 4133000; 694400, 4133100; 
694400, 4132000; 693700, 4132000; 693700, 4129800; 693700, 4127500; 
694500, 4127000; 694800, 4127000; 695200, 4127700; 695200, 4129800; 
695200, 4130300; 695700, 4130300; 695900, 4130000; 696100, 4129500; 
696100, 4129100; 696900, 4129100; 696900, 4130200; 697200, 4130200; 
698300, 4128600; 698600, 4128200; 700100, 4127600; 700500, 4129200; 
700500, 4130600; 701700, 4130600; 701800, 4129200; 703300, 4129200; 
703300, 4128800; 703900, 4128800; 703900, 4129000; 704200, 4129000; 
705600, 4128500; 705600, 4127800; 705300, 4127000; 705400, 4126200; 
705900, 4125700; 706800, 4125400; 707200, 4125400; 707900, 4126100; 
708300, 4126100; 708300, 4125400; 709100, 4125400; 709900, 4125700; 
709900, 4126000; 710200, 4126200; 711500, 4126200; 711500, 4124600; 
708000, 4124500; 706700, 4124500; 706700, 4122100; 711500, 4122200; 
711500, 4121700; 712100, 4121400; 713200, 4121400; 713200, 4118700; 
711600, 4118700; 711600, 4118100; 707300, 4118100; 705000, 4118100; 
704500, 4119600; 699400, 4119500; 699300, 4118700; 698800, 4118700; 
698500, 4118500; 698200, 4117700; 697600, 4117700; 697800, 4116500; 
693700, 4116200; 694200, 4115100; 694400, 4114600; 694800, 4114600; 
695000, 4115100; 695800, 4115100; 696300, 4114300; 697600, 4114200; 
697900, 4113900; 697900, 4113100; 698900, 4112500; 698800, 4109800; 
695700, 4109800; 695700, 4109000; 697300, 4109000; 697300, 4108100; 
696400, 4108100; 696400, 4107300; 696700, 4106600; 697600, 4106600; 
698200, 4105800; 698200, 4105300; returning to 697300, 4104500.
    (11) Unit 8: Ventura County, California.
    (i) From USGS 1:24,000 quadrangle maps Alamo Mountain, Lion Canyon, 
Lockwood Valley, San Guillermo, and Topatopa Mountains, California, 
land bounded by the following UTM 11 NAD 83 coordinates (E, N): 310100, 
3830500; 309400, 3831000; 308400, 3830900; 307200, 3830600; 306000, 
3831200; 304700, 3831300; 303400, 3832100; 302100, 3832600; 301600, 
3833600; 300400, 3833600; 299200, 3834000; 298200, 3834400; 297700, 
3835300; 297900, 3837300; 299500, 3837500; 301200, 3838400; 301500, 
3839300; 303400, 3841000; 303800, 3842700; 304900, 3843600; 305800, 
3843600; 307700, 3843400; 309500, 3843400; 310500, 3844200; 311900, 
3844600; 313400, 3845400; 314500, 3844100; 315200, 3843800; 315700, 
3842400; 316500, 3841100; 317200, 3838100; 317200, 3837000; 316500, 
3833900; 315700, 3833300; 315200, 3834100; 314000, 3834100; 313100, 
3832200; 311500, 3830800; returning to 310100, 3830500.
    (12) Map follows of all critical habitat units for Conservancy 
fairy shrimp (Branchinecta conservatio).
BILLING CODE 4310-55-P

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BILLING CODE 4310-55-C

Longhorn Fairy Shrimp (Branchinecta longiantenna)

    (1) Critical habitat units are depicted for Alameda, Contra Costa, 
Merced and San Luis Obispo counties, California, on the map below.
    (2) The primary constituent elements of critical habitat for 
Branchinecta longiantenna are the habitat components that provide:

[[Page 59976]]

    (i) Vernal pools, swales, and other ephemeral wetlands and 
depressions of appropriate sizes and depths that typically become 
inundated during winter rains and hold water for sufficient lengths of 
time necessary for Longhorn fairy shrimp incubation, reproduction, 
dispersal, feeding, and sheltering, including but not limited to large, 
playa vernal pools often on basin rim landforms and alkaline soils, but 
which are dry during the summer and do not necessarily fill with water 
every year; and
    (ii) The geographic, topographic, and edaphic features that support 
aggregations or systems of hydrologically interconnected pools, swales, 
and other ephemeral wetlands and depressions within a matrix of 
surrounding uplands that together form hydrologically and ecologically 
functional units called vernal pool complexes. These features 
contribute to the filling and drying of the vernal pool, and maintain 
suitable periods of pool inundation, water quality, and soil moisture 
for vernal pool crustacean hatching, growth and reproduction, and 
dispersal, but not necessarily every year.
    (3) Existing man-made features and structures, such as buildings, 
roads, railroads, airports, runways, other paved areas, lawns, and 
other urban landscaped areas do not contain one or more of the primary 
constituent elements. Federal actions limited to those areas, 
therefore, would not trigger a consultation under section 7 of the Act 
unless they may affect the species and/or primary constituent elements 
in adjacent critical habitat.
    (4) Subunit 1A: Contra Costa County, California.
    (i) From USGS 1:24,000 quadrangle map Byron Hot Springs, 
California, land bounded by the following UTM 10 NAD 83 coordinates (E, 
N): 614700, 4184000; 614600, 4184000; 614600, 4184500; 614900, 4185000; 
614600, 4185300; 614600, 4185900; 614700, 4185900; 614800, 4185400; 
615100, 4185200; 615100, 4185500; 615300, 4185500; 615400, 4185200; 
615600, 4184900; 615800, 4184900; 616000, 4184800; 616000, 4184700; 
615800, 4184500; 615700, 4184500; 615500, 4184200; 615100, 4184200; 
614800, 4184200; returning to 614700, 4184000.
    (5) Subunit 1B: Alameda County, California.
    (i) From USGS 1:24,000 quadrangle map Byron Hot Springs, 
California, land bounded by the following UTM 10 NAD 83 coordinates (E, 
N): 616200, 4179000; 616100, 4179000; 615900, 4179200; 615900, 4179400; 
615700, 4179600; 615500, 4180100; 615100, 4180500; 614800, 4180800; 
614400, 4180900; 614100, 4181100; 614600, 4181500; 614700, 4181500; 
614700, 4181700; 614900, 4181700; 615200, 4181400; 615400, 4181300; 
615500, 4181200; 615500, 4181100; 615600, 4181100; 615700, 4181300; 
615800, 4181200; 616000, 4180600; 616000, 4180500; 616200, 4180200; 
616300, 4180000; 616200, 4179900; 615900, 4179900; 615900, 4179700; 
616200, 4179500; returning to 616200, 4179000.
    (6) Unit 2: Merced County, California.
    (i) From USGS 1:24,000 quadrangle maps Gustine, Ingomar, Los Banos, 
San Luis Ranch, and Stevinson, California, land bounded by the 
following UTM 10 NAD 83 coordinates (E, N): 681200, 4117100; 681000, 
4124500; 680800, 4124900; 679800, 4124900; 679800, 4125700; 680700, 
4125700; 680600, 4126400; 680300, 4126700; 680300, 4127200; 678900, 
4127800; 679000, 4129000; 679300, 4129200; 680100, 4129400; 679700, 
4130700; 679400, 4130200; 678600, 4130200; 678000, 4131200; 678500, 
4132100; 678800, 4132400; 679000, 4131800; 679200, 4131800; 680200, 
4132200; 680700, 4131700; 681600, 4132800; 681200, 4133100; 681200, 
4133600; 681600, 4134100; 681700, 4134200; 681900, 4134200; 682300, 
4134000; 682700, 4133800; 683400, 4133100; 683600, 4132600; 683600, 
4132300; 683100, 4131800; thence south to x-coordinate 683100 on the 
San Joaquin River; thence southeast along to San Joaquin River to y-
coordinate 4118400; thence west to 698400, 4118400; 698200, 4117700; 
697600, 4117700; 697800, 4116500; 693700, 4116200; 694200, 4115100; 
694400, 4114600; 694800, 4114600; 695000, 4115100; 695800, 4115100; 
696300, 4114300; 697600, 4114200; 697900, 4113900; 697900, 4113100; 
698900, 4112500; 698800, 4109800; 695700, 4109800; 695700, 4109000; 
697300, 4109000; 697300, 4108100; 696400, 4108100; 696400, 4107300; 
696700, 4106600; 697600, 4106600; 698200, 4105800; 698200, 4105300; 
697300, 4104500; 696100, 4104500; 695700, 4105000; 695700, 4106600; 
694700, 4107900; 693500, 4107900; 693700, 4109100; 692900, 4109100; 
692900, 4109800; 693100, 4110200; 693800, 4110200; 693800, 4111800; 
692500, 4111800; 692400, 4110600; 691800, 4110600; 691600, 4110200; 
690800, 4110300; 690000, 4110300; 690000, 4111400; 689700, 4111800; 
689200, 4111800; 689200, 4111300; 688400, 4111300; 688400, 4112100; 
686700, 4112100; 686500, 4112900; 686500, 4113700; 686000, 4113700; 
686000, 4116100; 684500, 4116100; 684400, 4114200; 682200, 4114200; 
682100, 4113000; 681100, 4113000; 681100, 4111800; 680600, 4111700; 
679600, 4110900; 678800, 4110900; 678200, 4111800; 678300, 4113600; 
677900, 4114400; 679400, 4114400; 679400, 4115200; 680000, 4115200; 
680300, 4116000; 681800, 4116100; 682800, 4116600; 683600, 4116500; 
683600, 4117100; returning to 681200, 4117100.
    (7) Unit 3: San Luis Obispo County, California.
    (i) From USGS 1:24,000 quadrangle map Byron Hot Springs, 
California, land bounded by the following UTM 11 NAD 83 coordinates (E, 
N): 247900, 3894600; 245800, 3895500; 243500, 3896000; 242700, 3896400; 
242200, 3897600; 240100, 3898900; 239500, 3899300; 239300, 3899600; 
238300, 3900400; 237900, 3900300; 236100, 3901000; 235800, 3901300; 
235800, 3902300; 235500, 3903500; 234800, 3904400; 233000, 3904900; 
231800, 3905800; 231600, 3907000; 231900, 3908800; 231800, 3909400; 
229400, 3910200; 227200, 3911200; 227300, 3913400; 228100, 3913800; 
229000, 3913900; 231900, 3913200; 233300, 3913200; 234300, 3912900; 
235100, 3912100; 235300, 3911200; 233900, 3910100; 233700, 3909700; 
235300, 3909000; 235700, 3908500; 237200, 3907500; 237700, 3906300; 
238200, 3905800; 239100, 3905200; 239100, 3904900; 242800, 3902600; 
244400, 3901300; 244400, 3901000; 244700, 3900700; 244800, 3899100; 
245400, 3898800; 247200, 3896600; 248200, 3895000; returning to 247900, 
3894600.
    (8) Map follows of all critical habitat units for longhorn fairy 
shrimp (Branchinecta longiantenna):
BILLING CODE 4310-55-P

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BILLING CODE 4310-55-P

Vernal Pool Fairy Shrimp (Branchinecta lynchi)

    (1) Critical habitat units are depicted for Jackson County, Oregon; 
Shasta, Butte, Tehama, Glenn, Colusa, Placer, Sacramento, Solano, Napa, 
Contra Costa, Alameda, Amador, San Joaquin, Stanislaus, Merced, 
Mariposa, Madera, Fresno, Tulare, Kings, San Benito, Monterey, San Luis 
Obispo, Santa

[[Page 59978]]

Barbara, Ventura and Riverside counties, California on the map below:
    (2) The primary constituent elements of critical habitat for 
Branchinecta lynchi are the habitat components that provide--
    (i) Vernal pools, swales, and other ephemeral wetlands and 
depressions of appropriate sizes and depths that typically become 
inundated during winter rains and hold water for sufficient lengths of 
time necessary for vernal pool fairy shrimp incubation, reproduction, 
dispersal, feeding, and sheltering, including but not limited to 
Northern Hardpan, Northern Claypan, Northern Volcanic Mud Flow, and 
Northern Basalt Flow vernal pools formed on a variety of geologic 
formations and soil types, but which are dry during the summer and do 
not necessarily fill with water every year; and
    (ii) The geographic, topographic, and edaphic features that support 
aggregations or systems of hydrologically interconnected pools, swales, 
and other ephemeral wetlands and depressions within a matrix of 
surrounding uplands that together form hydrologically and ecologically 
functional units called vernal pool complexes. These features 
contribute to the filling and drying of the vernal pool, and maintain 
suitable periods of pool inundation, water quality, and soil moisture 
for vernal pool crustacean hatching, growth and reproduction, and 
dispersal, but not necessarily every year.
    (3) Existing man-made features and structures, such as buildings, 
roads, railroads, airports, runways, other paved areas, lawns, and 
other urban landscaped areas do not contain one or more of the primary 
constituent elements. Federal actions limited to those areas, 
therefore, would not trigger a consultation under section 7 of the Act 
unless they may affect the species and/or primary constituent elements 
in adjacent critical habitat.
    (4) Subunit 1A: Jackson County, Oregon.
    (i) From USGS 1:24,000 quadrangle map Shady Cove, Oregon, land 
bounded by the following UTM 10 NAD 83 coordinates (E, N): 513900, 
4709700; 513600, 4709700; 513600, 4709800; 513500, 4709800; 513500, 
4710000; 513700, 4710000; 513700, 4710300; 513200, 4710300; 513200, 
4710600; 513100, 4710600; 513100, 4710800; 514300, 4710800; 514300, 
4710300; 514100, 4710300; 514100, 4709900; 513900, 4709900; returning 
to 513900, 4709700.
    (5) Subunit 1B: Jackson County, Oregon.
    (i) From USGS 1:24,000 quadrangle map Shady Cove, Oregon, land 
bounded by the following UTM 10 NAD 83 coordinates (E, N): 513900, 
4707000; 513600, 4707000; 513600, 4707300; 513700, 4707300; 513700, 
4707400; 513800, 4707400; 513800, 4707500; 513400, 4707500; 513400, 
4708000; 514700, 4708000; 514700, 4707700; 514600, 4707700; 514600, 
4707600; 514200, 4707600; 514200, 4707500; 514100, 4707500; 514100, 
4707300; 514000, 4707300; 514000, 4707200; 513900, 4707200; returning 
to 513900, 4707000.
    (6) Subunit 1C: Jackson County, Oregon.
    (i) From USGS 1:24,000 quadrangle map Shady Cove, Oregon, land 
bounded by the following UTM 10 NAD 83 coordinates (E, N): 512000, 
4706600; 511800, 4706600; 511800, 4706700; 511300, 4706700; 511300, 
4706800; 511200, 4706800; 511200, 4706900; 511100, 4706900; 511100, 
4707000; 511000, 4707000; 511000, 4707200; 511100, 4707200; 511100, 
4707300; 511200, 4707300; 511200, 4707400; 511100, 4707400; 511100, 
4707500; 511200, 4707500; 511200, 4707600; 511400, 4707600; 511400, 
4707700; 511600, 4707700; 511600, 4707800; 511800, 4707800; 511800, 
4707300; 511900, 4707300; 511900, 4706800; 512000, 4706800; returning 
to 512000, 4706600.
    (7) Subunit 1D: Jackson County, Oregon.
    (i) From USGS 1:24,000 quadrangle maps Eagle Point and Shady Cove, 
Oregon, land bounded by the following UTM 10 NAD 83 coordinates (E, N): 
515900, 4706700; 515900, 4707000; 516200, 4707000; 516200, 4706900; 
516300, 4706900; 516300, 4706700; 516400, 4706700; 516400, 4706800; 
516500, 4706800; 516500, 4707000; 516700, 4707000; 516700, 4706900; 
516900, 4706900; 516900, 4707000; 517000, 4707000; 517000, 4707100; 
517100, 4707100; 517100, 4706900; 517400, 4706900; 517400, 4706700; 
517300, 4706700; 517300, 4706500; 517200, 4706500; 517200, 4706400; 
517100, 4706400; 517100, 4706300; 516700, 4706300; 516700, 4705600; 
516500, 4705600; 516500, 4705500; 516600, 4705500; 516600, 4705400; 
516700, 4705400; 516700, 4704800; 516600, 4704800; 516600, 4704600; 
516300, 4704600; 516300, 4704500; 516400, 4704500; 516400, 4704400; 
516500, 4704400; 516500, 4704300; 515800, 4704300; 515800, 4704600; 
516000, 4704600; 516000, 4704700; 515500, 4704700; 515500, 4704800; 
515400, 4704800; 515400, 4705100; 515500, 4705100; 515500, 4705200; 
515700, 4705200; 515700, 4705300; 515800, 4705300; 515800, 4705900; 
515700, 4705900; 515700, 4706200; 515600, 4706200; 515600, 4706400; 
515500, 4706400; 515500, 4706500; 515100, 4706500; 515100, 4706700; 
515000, 4706700; 515000, 4706900; 514700, 4706900; 514700, 4707000; 
514600, 4707000; 514600, 4707200; 514700, 4707200; 514700, 4707300; 
515000, 4707300; 515000, 4707200; 515100, 4707200; 515100, 4707100; 
515200, 4707100; 515200, 4707000; 515300, 4707000; 515300, 4706800; 
515400, 4706800; 515400, 4706700; 515500, 4706700; 515500, 4706600; 
515600, 4706600; 515600, 4706700; returning to 515900, 4706700; 
excluding land bounded by 515900, 4706700; 515900, 4706500; 516000, 
4706500; 516000, 4706400; 516100, 4706400; 516100, 4706600; 516000, 
4706600; 516000, 4706700; 515900, 4706700.
    (8) Subunit 1E: Jackson County, Oregon.
    (i) From USGS 1:24,000 quadrangle maps Boswell Mountain and Shady 
Cove, Oregon, land bounded by the following UTM 10 NAD 83 coordinates 
(E, N): 510500, 4706000; 510400, 4706000; 510400, 4706100; 510300, 
4706100; 510300, 4706300; 510100, 4706300; 510100, 4706400; 510000, 
4706400; 510000, 4706500; 509800, 4706500; 509800, 4706700; 510000, 
4706700; 510000, 4706900; 510100, 4706900; 510100, 4707000; 510200, 
4707000; 510200, 4706900; 510500, 4706900; 510500, 4707000; 510600, 
4707000; 510600, 4707100; 510800, 4707100; 510800, 4706900; 511000, 
4706900; 511000, 4706500; 510700, 4706500; 510700, 4706300; 510500, 
4706300; returning to 510500, 4706000.
    (9) Subunit 1F: Jackson County, Oregon.
    (i) From USGS 1:24,000 quadrangle maps Eagle Point and Shady Cove, 
Oregon, land bounded by the following UTM 10 NAD 83 coordinates (E, N): 
511400, 4704800; 511200, 4704800; 511200, 4705000; 511000, 4705000; 
511000, 4705200; 510900, 4705200; 510900, 4705300; 510800, 4705300; 
510800, 4705900; 511000, 4705900; 511000, 4706000; 511300, 4706000; 
511300, 4705900; 511500, 4705900; 511500, 4705100; 511400, 4705100; 
returning to 511400, 4704800; excluding land bounded by 511300, 
4705300; 511300, 4705500; 511200, 4705500; 511200, 4705300; 511300, 
4705300.
    (10) Subunit 1G: Jackson County, Oregon.
    (i) From USGS 1:24,000 quadrangle map Eagle Point, Oregon, land 
bounded by the following UTM 10 NAD 83 coordinates (E, N): 517700, 
4704000; 517200, 4704000; 517200, 4704100; 517100, 4704100; 517100, 
4704300;

[[Page 59979]]

517000, 4704300; 517000, 4704700; 516900, 4704700; 516900, 4704900; 
517000, 4704900; 517000, 4705000; 517100, 4705000; 517100, 4705100; 
517600, 4705100; 517600, 4705000; 517800, 4705000; 517800, 4704900; 
517900, 4704900; 517900, 4704800; 519100, 4704800; 519100, 4704700; 
519300, 4704700; 519300, 4704600; 519400, 4704600; 519400, 4704300; 
519100, 4704300; 519100, 4704200; 518600, 4704200; 518600, 4704100; 
517900, 4704100; 517900, 4704200; 517700, 4704200; returning to 517700, 
4704000.
    (11) Unit 2A: Jackson County, Oregon.
    (i) From USGS 1:24,000 quadrangle map Eagle Point, Oregon, land 
bounded by the following UTM 10 NAD 83 coordinates (E, N): 514300, 
4698400; 513400, 4698400; 513400, 4698500; 513300, 4698500; 513300, 
4698600; 513400, 4698600; 513400, 4698700; 513500, 4698700; 513500, 
4698800; 513700, 4698800; 513700, 4699000; 513800, 4699000; 513800, 
4699100; 513900, 4699100; 513900, 4699200; 514200, 4699200; 514200, 
4698800; 514300, 4698800; 514300, 4698900; 514400, 4698900; 514400, 
4699000; 514900, 4699000; 514900, 4698900; 515100, 4698900; 515100, 
4699100; 515200, 4699100; 515200, 4699000; 515500, 4699000; 515500, 
4698800; 515600, 4698800; 515600, 4699000; 515700, 4699000; 515700, 
4698900; 515800, 4698900; 515800, 4698500; 515500, 4698500; 515500, 
4698700; 515400, 4698700; 515400, 4698600; 515300, 4698600; 515300, 
4698500; 515100, 4698500; 515100, 4698600; 514900, 4698600; 514900, 
4698500; 514400, 4698500; 514400, 4698600; 514300, 4698600; returning 
to 514300, 4698400.
    (12) Subunit 2B: Jackson County, Oregon.
    (i) From USGS 1:24,000 quadrangle maps Brownsboro and Eagle Point, 
Oregon, land bounded by the following UTM 10 NAD 83 coordinates (E, N): 
520800, 4694400; 520700, 4694400; 520700, 4694500; 520500, 4694500; 
520500, 4694600; 520400, 4694600; 520400, 4694700; 520300, 4694700; 
520300, 4694800; 519900, 4694800; 519900, 4694900; 519500, 4694900; 
519500, 4695200; 519400, 4695200; 519400, 4695600; 519300, 4695600; 
519300, 4695800; 519200, 4695800; 519200, 4695900; 519100, 4695900; 
519100, 4696000; 519000, 4696000; 519000, 4696200; 519300, 4696200; 
519300, 4696300; 519100, 4696300; 519100, 4696400; 518900, 4696400; 
518900, 4696500; 518800, 4696500; 518800, 4696400; 518600, 4696400; 
518600, 4696700; 518500, 4696700; 518500, 4696800; 518400, 4696800; 
518400, 4696900; 518300, 4696900; 518300, 4697000; 518200, 4697000; 
518200, 4697100; 518100, 4697100; 518100, 4697200; 517600, 4697200; 
517600, 4697300; 517300, 4697300; 517300, 4697400; 517100, 4697400; 
517100, 4697600; 517000, 4697600; 517000, 4697800; 516900, 4697800; 
516900, 4698400; 517300, 4698400; 517300, 4698300; 517500, 4698300; 
517500, 4698200; 517600, 4698200; 517600, 4698300; 517900, 4698300; 
517900, 4697800; 518500, 4697800; 518500, 4697700; 518600, 4697700; 
518600, 4697600; 518800, 4697600; 518800, 4697700; 519100, 4697700; 
519100, 4697600; 519300, 4697600; 519300, 4697500; 519400, 4697500; 
519400, 4697400; 519500, 4697400; 519500, 4697300; 519700, 4697300; 
519700, 4697200; 519800, 4697200; 519800, 4697100; 520000, 4697100; 
520000, 4696800; 519900, 4696800; 519900, 4696700; 520400, 4696700; 
520400, 4696600; 520500, 4696600; 520500, 4696300; 520400, 4696300; 
520400, 4696100; 520500, 4696100; 520500, 4696200; 520600, 4696200; 
520600, 4696100; 520700, 4696100; 520700, 4695900; 520600, 4695900; 
520600, 4695800; 520500, 4695800; 520500, 4695500; 520700, 4695500; 
520700, 4695400; 520800, 4695400; returning to 520800, 4694400.
    (13) Subunit 2C: Jackson County, Oregon.
    (i) From USGS 1:24,000 quadrangle map Eagle Point, Oregon, land 
bounded by the following UTM 10 NAD 83 coordinates (E, N): 516100, 
4697400; 515000, 4697400; 515000, 4697800; 515200, 4697800; 515200, 
4697700; 515300, 4697700; 515300, 4697800; 516100, 4697800; returning 
to 516100, 4697400.
    (14) Subunit 2D: Jackson County, Oregon.
    (i) From USGS 1:24,000 quadrangle map Eagle Point, Oregon, land 
bounded by the following UTM 10 NAD 83 coordinates (E, N): 516200, 
4696200; 515900, 4696200; 515900, 4696900; 516100, 4696900; 516100, 
4697000; 516500, 4697000; 516500, 4697100; 516800, 4697100; 516800, 
4697200; 517000, 4697200; 517000, 4697100; 517200, 4697100; 517200, 
4697000; 517300, 4697000; 517300, 4696900; 517400, 4696900; 517400, 
4696600; 517200, 4696600; 517200, 4696700; 516800, 4696700; 516800, 
4696600; 516300, 4696600; 516300, 4696500; 516200, 4696500; returning 
to 516200, 4696200.
    (15) Subunit 2E: Jackson County, Oregon.
    (i) From USGS 1:24,000 quadrangle map Eagle Point, Oregon, land 
bounded by the following UTM 10 NAD 83 coordinates (E, N): 515200, 
4695800; 515000, 4695800; 515000, 4695900; 514500, 4695900; 514500, 
4695800; 514300, 4695800; 514300, 4695900; 514200, 4695900; 514200, 
4696000; 514100, 4696000; 514100, 4695900; 514000, 4695900; 514000, 
4695800; 513900, 4695800; 513900, 4695900; 513800, 4695900; 513800, 
4696600; 513500, 4696600; 513500, 4696800; 515600, 4696800; 515600, 
4696600; 515500, 4696600; 515500, 4696400; 515100, 4696400; 515100, 
4696300; 515200, 4696300; returning to 515200, 4695800; excluding land 
bounded by 514700, 4696300; 514700, 4696500; 514500, 4696500; 514500, 
4696400; 514300, 4696400; 514300, 4696500; 514200, 4696500; 514200, 
4696400; 514100, 4696400; 514100, 4696300; 514700, 4696300.
    (16) Subunit 3A: Jackson County, Oregon.
    (i) From USGS 1:24,000 quadrangle map Eagle Point, Oregon, land 
bounded by the following UTM 10 NAD 83 coordinates (E, N): 511600, 
4698900; 511600, 4699000; 511400, 4699000; 511400, 4699100; 511100, 
4699100; 511100, 4699200; 510700, 4699200; 510700, 4699300; 510600, 
4699300; 510600, 4699500; 510900, 4699500; 510900, 4699600; 511200, 
4699600; 511200, 4699700; 511300, 4699700; 511300, 4699900; 511400, 
4699900; 511400, 4700000; 511500, 4700000; 511500, 4699900; 511600, 
4699900; 511600, 4699800; 511700, 4699800; 511700, 4699900; 511900, 
4699900; 511900, 4698900; returning to 511600, 4698900.
    (17) Subunit 3B: Jackson County, Oregon.
    (i) From USGS 1:24,000 quadrangle maps Eagle Point and Sams Valley, 
Oregon, land bounded by the following UTM 10 NAD 83 coordinates (E, N): 
511600, 4698900; 511600, 4698600; 511300, 4698600; 511300, 4698700; 
511200, 4698700; 511200, 4698600; 511000, 4698600; 511000, 4698500; 
510700, 4698500; 510700, 4698600; 510500, 4698600; 510500, 4698500; 
509600, 4698500; 509600, 4698100; 509400, 4698100; 509400, 4698000; 
509200, 4698000; 509200, 4697800; 509300, 4697800; 509300, 4697600; 
509400, 4697600; 509400, 4697200; 509500, 4697200; 509500, 4697000; 
510100, 4697000; 510100, 4697100; 511700, 4697100; 511700, 4697000; 
511900, 4697000; 511900, 4696400; 510800, 4696400; 510800, 4696300; 
510600, 4696300; 510600, 4696400; 510300, 4696400; 510300, 4696500; 
509700, 4696500; 509700, 4696600; 509600, 4696600; 509600, 4696500; 
508900, 4696500; 508900, 4696600; 508600, 4696600; 508600, 4696700;

[[Page 59980]]

508400, 4696700; 508400, 4696800; 508300, 4696800; 508300, 4696900; 
508200, 4696900; 508200, 4697000; 508100, 4697000; 508100, 4697100; 
508000, 4697100; 508000, 4697300; 508100, 4697300; 508100, 4697600; 
508400, 4697600; 508400, 4697700; 508600, 4697700; 508600, 4697800; 
508500, 4697800; 508500, 4698000; 508400, 4698000; 508400, 4698400; 
508500, 4698400; 508500, 4698500; 508800, 4698500; 508800, 4698600; 
508900, 4698600; 508900, 4698300; 509000, 4698300; 509000, 4698400; 
509100, 4698400; 509100, 4698600; 509200, 4698600; 509200, 4698700; 
509500, 4698700; 509500, 4698900; 509800, 4698900; 509800, 4699000; 
510100, 4699000; 510100, 4699100; 511000, 4699100; 511000, 4699000; 
511300, 4699000; 511300, 4698900; returning to 511600, 4698900; 
excluding land bounded by 508600, 4697100; 508600, 4697300; 508500, 
4697300; 508500, 4697100; 508600, 4697100; and land bounded by 509100, 
4697700; 509100, 4697800; 508800, 4697800; 508800, 4697700; 509100, 
4697700.
    (18) Subunit 3C: Jackson County, Oregon.
    (i) From USGS 1:24,000 quadrangle map Sams Valley, Oregon, land 
bounded by the following UTM 10 NAD 83 coordinates (E, N): 508300, 
4695000; 507800, 4695000; 507800, 4695200; 507400, 4695200; 507400, 
4695400; 506900, 4695400; 506900, 4695800; 506800, 4695800; 506800, 
4695900; 506400, 4695900; 506400, 4695800; 505600, 4695800; 505600, 
4696000; 505800, 4696000; 505800, 4696700; 506200, 4696700; 506200, 
4696800; 506100, 4696800; 506100, 4697300; 506200, 4697300; 506200, 
4697600; 506800, 4697600; 506800, 4697500; 506900, 4697500; 506900, 
4697300; 506800, 4697300; 506800, 4697200; 506700, 4697200; 506700, 
4696700; 507000, 4696700; 507000, 4697000; 506900, 4697000; 506900, 
4697200; 507000, 4697200; 507000, 4697400; 507100, 4697400; 507100, 
4697500; 507200, 4697500; 507200, 4697400; 507300, 4697400; 507300, 
4697300; 507400, 4697300; 507400, 4697100; 507500, 4697100; 507500, 
4697000; 507600, 4697000; 507600, 4696900; 507700, 4696900; 507700, 
4696700; 507900, 4696700; 507900, 4696000; 508300, 4696000; returning 
to 508300, 4695000.
    (19) Subunit 4A: Jackson County, Oregon.
    (i) From USGS 1:24,000 quadrangle map Sams Valley, Oregon, land 
bounded by the following UTM 10 NAD 83 coordinates (E, N): 508600, 
4701300; 508400, 4701300; 508400, 4701500; 508300, 4701500; 508300, 
4701900; 508200, 4701900; 508200, 4702000; 508100, 4702000; 508100, 
4702100; 508000, 4702100; 508000, 4702200; 507900, 4702200; 507900, 
4702300; 507800, 4702300; 507800, 4702400; 507700, 4702400; 507700, 
4702500; 507600, 4702500; 507600, 4702400; 507500, 4702400; 507500, 
4702300; 507300, 4702300; 507300, 4702200; 507400, 4702200; 507400, 
4702100; 507600, 4702100; 507600, 4702000; 507700, 4702000; 507700, 
4701800; 507800, 4701800; 507800, 4701700; 507900, 4701700; 507900, 
4701400; 507700, 4701400; 507700, 4701500; 507600, 4701500; 507600, 
4701600; 507300, 4701600; 507300, 4701700; 507100, 4701700; 507100, 
4701800; 507000, 4701800; 507000, 4701900; 506900, 4701900; 506900, 
4702000; 506800, 4702000; 506800, 4702200; 506700, 4702200; 506700, 
4702400; 506600, 4702400; 506600, 4702500; 506500, 4702500; 506500, 
4702700; 506600, 4702700; 506600, 4702900; 506700, 4702900; 506700, 
4703100; 506800, 4703100; 506800, 4703400; 507000, 4703400; 507000, 
4703500; 507200, 4703500; 507200, 4703400; 507300, 4703400; 507300, 
4703300; 507800, 4703300; 507800, 4703200; 507900, 4703200; 507900, 
4703100; 508000, 4703100; 508000, 4703000; 508100, 4703000; 508100, 
4702900; 508200, 4702900; 508200, 4702800; 508300, 4702800; 508300, 
4702700; 508400, 4702700; 508400, 4702500; 508500, 4702500; 508500, 
4702300; 508600, 4702300; 508600, 4701900; 508800, 4701900; 508800, 
4701500; 508700, 4701500; 508700, 4701400; 508600, 4701400; returning 
to 508600, 4701300.
    (20) Subunit 4B: Jackson County, Oregon.
    (i) From USGS 1:24,000 quadrangle map Sams Valley, Oregon, land 
bounded by the following UTM 10 NAD 83 coordinates (E, N): 504000, 
4698900; 503800, 4698900; 503800, 4699000; 503700, 4699000; 503700, 
4699400; 503800, 4699400; 503800, 4699800; 503700, 4699800; 503700, 
4700900; 503800, 4700900; 503800, 4700800; 503900, 4700800; 503900, 
4700700; 504000, 4700700; 504000, 4700600; 504300, 4700600; 504300, 
4700500; 504400, 4700500; 504400, 4699500; 504200, 4699500; 504200, 
4699200; 504100, 4699200; 504100, 4699100; 504000, 4699100; returning 
to 504000, 4698900.
    (21) Unit 5: Shasta County, California.
    (i) From USGS 1:24,000 quadrangle maps Balls Ferry, Cottonwood, 
Enterprise, and Palo Cedro, California, land bounded by the following 
UTM 10 NAD 83 coordinates (E, N): 564200, 4480800; 564000, 4480800; 
563600, 4480900; 563300, 4481000; 563100, 4480900; 562900, 4480900; 
562500, 4481200; 562400, 4481500; 562400, 4481700; 562300, 4482400; 
562000, 4482500; 561900, 4482800; 561800, 4483300; 561500, 4483700; 
561000, 4484000; 560700, 4485400; 560700, 4486500; 560800, 4486700; 
561000, 4486900; 561200, 4487000; 561300, 4487600; 561600, 4487900; 
562000, 4487900; 562500, 4487400; 562700, 4487100; 562900, 4487200; 
563200, 4487200; 563300, 4487000; 563300, 4486700; 563800, 4486400; 
564300, 4484700; 564300, 4484400; 564700, 4483800; 564900, 4483600; 
564900, 4483400; 564500, 4483000; 564500, 4482800; 564600, 4482700; 
564600, 4482400; 564400, 4482100; 564500, 4481700; 564500, 4481000; 
returning to 564200, 4480800.
    (22) Unit 6: Tehama County, California.
    (i) From USGS 1:24,000 quadrangle maps Corning, Gerber, 
Henleyville, Red Bluff East, Red Bluff West, and West of Gerber, 
California, land bounded by the following UTM 10 NAD 83 coordinates (E, 
N): 555600, 4423000; 555100, 4423000; 554600, 4424900; 555100, 4425600; 
557200, 4426300; 557800, 4426800; 558300, 4426500; 559500, 4428300; 
558200, 4428200; 557800, 4428500; 557400, 4429300; 558000, 4429900; 
558600, 4430000; 558600, 4431100; 560000, 4431600; 559200, 4431900; 
558300, 4432000; 557400, 4432200; 557400, 4432600; 558400, 4433100; 
558400, 4433600; 557800, 4433600; 557500, 4433800; 557300, 4434400; 
555100, 4434800; 555100, 4435400; 557000, 4436200; 557900, 4439000; 
557000, 4439000; 554600, 4437400; 553200, 4437000; 553200, 4437600; 
554500, 4438100; 555400, 4439700; 556500, 4439800; 556500, 4441800; 
558500, 4442600; 558500, 4443000; 557400, 4442900; 557000, 4443000; 
556800, 4443400; 557500, 4444300; 558000, 4443700; 558400, 4443700; 
559900, 4444000; 559900, 4444700; 559800, 4444700; 559800, 4445400; 
560900, 4446100; 562200, 4445400; 563000, 4445800; 563300, 4445800; 
563500, 4444400; 564400, 4444400; 565300, 4443400; 566400, 4443200; 
566500, 4442400; 566000, 4441500; 565400, 4441200; 565500, 4441000; 
566000, 4440600; 567500, 4441200; 567900, 4441200; 568900, 4440400; 
568400, 4440200; 568800, 4439400; 569400, 4439600; 570300, 4437900; 
569300, 4438000; 568100, 4438300; 567000, 4438000; 566800, 4437300; 
566200, 4437200; 566200, 4438200; 565900, 4438400; 565400, 4438000; 
564200, 4438000; 564200, 4437300; 563700, 4436700; 564800, 4436800; 
565100, 4435800; 563900,

[[Page 59981]]

4434600; 563900, 4432900; 563500, 4432100; 567300, 4431600; 567900, 
4427300; 566300, 4426600; 565000, 4425900; 563700, 4425800; 562000, 
4424700; 560400, 4424700; 558600, 4423800; returning to 555600, 
4423000.
    (23) Unit 7: Butte and Tehama counties, California.
    (i) From USGS 1:24,000 quadrangle maps Balls Ferry, Cottonwood, 
Enterprise, and Palo Cedro, California, land bounded by the following 
UTM 10 NAD 83 coordinates (E, N): 602400, 4401600; 601900, 4401800; 
601800, 4402000; 601500, 4401900; 601000, 4401900; 600400, 4402100; 
599600, 4402100; 599400, 4403400; 599100, 4403200; 598300, 4403400; 
597100, 4403700; 596400, 4404200; 596300, 4404800; 595100, 4405000; 
595100, 4405600; 595400, 4406000; 595400, 4407100; 595500, 4407100; 
595700, 4407300; 595700, 4407400; 596100, 4407400; 596400, 4408000; 
596400, 4408100; 596100, 4408200; 596100, 4408400; 596200, 4408600; 
595900, 4408800; 595700, 4408800; 595500, 4408200; 594300, 4408200; 
594100, 4408300; 594000, 4408400; 593600, 4408500; 593400, 4408200; 
592600, 4408200; 592500, 4408700; 592100, 4408500; 592000, 4408700; 
591400, 4408700; 590700, 4408700; 590400, 4408300; 589900, 4408300; 
589000, 4408600; 589000, 4409300; 589100, 4409900; 588900, 4410200; 
588200, 4410300; 588200, 4411000; 587900, 4411400; 587900, 4412000; 
587900, 4412400; 587600, 4412700; 587600, 4413400; 584200, 4413400; 
583100, 4413100; 582900, 4413400; 582900, 4415900; 582000, 4418300; 
581800, 4419200; 582000, 4419500; 581400, 4420000; 581400, 4420400; 
581800, 4420700; 581600, 4421000; 583200, 4422600; 583500, 4423600; 
585200, 4424500; 586000, 4424500; 587500, 4426100; 588200, 4426500; 
588600, 4429100; 588800, 4430200; 589500, 4429500; 589500, 4428600; 
591400, 4425800; 592600, 4424100; 593400, 4422300; 594200, 4421100; 
595900, 4417800; 595800, 4417300; 595800, 4416600; 596100, 4416600; 
596400, 4416800; 596600, 4416800; 597100, 4416400; 597100, 4415600; 
596800, 4415200; 597100, 4415000; 597800, 4415500; 598100, 4415200; 
597600, 4414600; 597600, 4414400; 597300, 4413800; 597300, 4413300; 
598200, 4413900; 598400, 4413900; 598400, 4413600; 597400, 4411900; 
597600, 4411900; 598300, 4412700; 598500, 4413300; 598900, 4413300; 
598900, 4411800; 599400, 4411700; 599800, 4411700; 599800, 4411000; 
597700, 4409400; 597000, 4408500; 596800, 4408300; 596800, 4407500; 
597300, 4407500; 597300, 4408000; 597900, 4407500; 598100, 4407500; 
598100, 4407100; 597700, 4406800; 597800, 4406700; 597500, 4406500; 
597300, 4406700; 597100, 4406600; 597500, 4406100; 597100, 4405900; 
597600, 4405100; 598000, 4405300; 598400, 4404700; 598500, 4404800; 
598200, 4405300; 599000, 4405800; 598900, 4406100; 598700, 4406000; 
598500, 4406000; 598500, 4407200; 598300, 4407200; 598300, 4407500; 
598200, 4407800; 598700, 4408400; 599900, 4409000; 600100, 4409000; 
600300, 4408800; 600300, 4408400; 600000, 4408100; 600400, 4407600; 
599500, 4406700; 599500, 4406200; 600300, 4406000; 601200, 4405600; 
601800, 4405600; 602000, 4405500; 602200, 4405200; 602500, 4405200; 
602700, 4404900; 603300, 4404700; 604500, 4404200; 605200, 4404200; 
605600, 4404000; 605600, 4403600; 605100, 4403300; 604700, 4403400; 
604500, 4403300; 604400, 4402800; 603600, 4402100; 602900, 4402100; 
returning to 602400, 4401600.
    (24) Unit 8: Glenn and Tehama counties, California.
    (i) From USGS 1:24,000 quadrangle maps Black Butte Dam and 
Kirkwood, California, land bounded by the following UTM 10 NAD 83 
coordinates (E, N): 560000, 4405200; 559200, 4405700; 558600, 4405800; 
558600, 4406400; 558600, 4408000; 558900, 4408700; 559100, 4408700; 
559400, 4407000; 560600, 4407000; 560600, 4407400; 561000, 4407400; 
561000, 4411400; 561800, 4411400; 565600, 4411400; 565600, 4410600; 
568400, 4410600; 568400, 4411400; 570500, 4411400; 570800, 4411700; 
571400, 4411500; 571500, 4411000; 572100, 4410900; 572100, 4410100; 
571800, 4409600; 570500, 4409000; 570200, 4409000; 570200, 4409300; 
569700, 4409300; 569700, 4409000; 569800, 4407700; 569900, 4407000; 
569800, 4406100; 569800, 4405500; 569400, 4405500; 568600, 4405900; 
568300, 4405900; 567500, 4405500; 567200, 4405500; 565000, 4405500; 
564600, 4405800; 564100, 4405800; 563700, 4405600; 563400, 4405400; 
562000, 4405700; 561100, 4405900; 560300, 4405900; 560200, 4405300; 
returning to 560000, 4405200.
    (25) Unit 9: Butte County, California.
    (i) From USGS 1:24,000 quadrangle maps Chico and Hamlin Canyon, 
California, land bounded by the following UTM 10 NAD 83 coordinates (E, 
N): 604600, 4395600; 604000, 4395700; 603900, 4396700; 603600, 4396800; 
603600, 4398000; 602900, 4398200; 603000, 4398800; 603100, 4399000; 
602600, 4399400; 602600, 4399600; 603500, 4399800; 604700, 4400200; 
605100, 4399600; 606500, 4399500; 607200, 4399100; 607400, 4399100; 
607700, 4398100; 607700, 4397800; 606200, 4396500; 606200, 4395800; 
returning to 604600, 4395600.
    (26) Unit 10: Colusa and Glenn counties, California.
    (i) From USGS 1:24,000 quadrangle maps Logandale, Maxwell, Moulton 
Weir, and Princeton, California, land bounded by the following UTM 10 
NAD 83 coordinates (E, N): 572900, 4357400; 571200, 4357400; 571200, 
4358200; 570400, 4358200; 570400, 4359000; 569600, 4359000; 569500, 
4360500; 569300, 4362200; 569500, 4363300; 569500, 4367200; 570000, 
4367200; 569900, 4368400; 570300, 4368400; 571000, 4367600; 571000, 
4367800; 570700, 4368500; 570900, 4368800; 571500, 4368800; 571900, 
4368300; 571900, 4367600; 572100, 4367600; 572400, 4368100; 572400, 
4368400; 572600, 4368900; 572800, 4368900; 573000, 4368100; 573400, 
4368000; 573800, 4367600; 574100, 4367300; 574400, 4367200; 574500, 
4366400; 574900, 4366400; 574900, 4365600; 574700, 4365500; 574400, 
4364100; 575200, 4363900; 575600, 4363600; 575100, 4362400; 575600, 
4361400; 575100, 4360700; 576000, 4359600; 575500, 4358900; 575700, 
4358300; 575900, 4357700; 575300, 4357800; 575000, 4357700; 574700, 
4357700; 573600, 4357800; 573500, 4358200; 572900, 4358200; returning 
to 572900, 4357400.
    (27) Unit 11: Yuba County, California.
    (i) From USGS 1:24,000 quadrangle maps Browns Valley and Wheatland, 
California, land bounded by the following UTM 10 NAD 83 coordinates (E, 
N): 636300, 4327700; 635600, 4327700; 635300, 4327800; 635300, 4328800; 
634800, 4329000; 634800, 4329700; 634600, 4329900; 633800, 4329900; 
633600, 4330100; 633500, 4330100; 632800, 4329700; 632700, 4328800; 
631300, 4328800; 631300, 4329300; 631400, 4329300; 631400, 4330600; 
632400, 4330700; 632800, 4330700; 633000, 4330900; 633000, 4331300; 
633100, 4331500; 633500, 4331700; 633800, 4331500; 633800, 4332300; 
631500, 4332200; 631500, 4333900; 632400, 4333900; 632400, 4335400; 
633300, 4335800; 633700, 4336300; 634100, 4336400; 634900, 4336700; 
635100, 4336600; 635200, 4336400; 635700, 4336400; 636000, 4336400; 
636100, 4335900; 635900, 4335800; 636000, 4335200; 636500, 4335100; 
637100, 4335300; 637400, 4334700; 637800, 4334700; 637700, 4333600; 
638200, 4333400; 638200, 4332600; 637600, 4332600; 637600, 4331900; 
636900, 4332100; 636700, 4332300; 636600, 4332500; 636100, 4334000; 
636700, 4334300; 636600,

[[Page 59982]]

4334500; 636000, 4334200; 635400, 4336000; 634500, 4336000; 634500, 
4335100; 634400, 4334700; 635100, 4332600; 636000, 4330500; 636400, 
4330300; 636500, 4329300; 637100, 4328800; 636900, 4327900; returning 
to 636300, 4327700.
    (28) Unit 12: Placer and Sacramento counties, California.
    (i) From USGS 1:24,000 quadrangle maps Citrus Heights, Gold Hill, 
Lincoln, Pleasant Grove, Rio Linda, Rocklin, Roseville, and Sheridan, 
California, land bounded by the following UTM 10 NAD 83 coordinates (E, 
N): 636500, 4287700; 635700, 4287700; 635100, 4288300; 634500, 4288300; 
634100, 4288500; 633600, 4288700; 632800, 4288700; 632800, 4289200; 
633100, 4289200; 634100, 4289900; 634100, 4290500; 634400, 4290600; 
634100, 4290800; 633700, 4290800; 633500, 4291200; 633700, 4291500; 
634600, 4291400; 634900, 4291200; 634900, 4290500; 635700, 4290400; 
637100, 4290400; 638100, 4290700; 637900, 4292300; 638300, 4293000; 
638800, 4293000; 638900, 4294200; 637100, 4294200; 637100, 4295500; 
638100, 4295500; 638300, 4295900; 638900, 4295900; 639100, 4295400; 
640000, 4295400; 640000, 4295800; 639300, 4296200; 639200, 4296700; 
639100, 4296900; 639000, 4298300; 638600, 4297500; 637500, 4297400; 
636900, 4297100; 636300, 4296900; 635600, 4297200; 635100, 4297200; 
634300, 4297100; 633500, 4297100; 633500, 4297800; 635100, 4297900; 
635100, 4298400; 635800, 4298600; 635800, 4300000; 636000, 4300100; 
636000, 4301000; 637800, 4300900; 637800, 4300300; 639200, 4300300; 
639200, 4301000; 639800, 4301000; 639800, 4301500; 637600, 4301500; 
637600, 4301900; 638400, 4302200; 639100, 4302300; 639900, 4302200; 
640000, 4301800; 640800, 4301800; 640800, 4302500; 641200, 4302700; 
641500, 4302700; 641600, 4302200; 641900, 4301900; 642200, 4302300; 
642800, 4301900; 643400, 4301400; 643700, 4302100; 644300, 4302300; 
644400, 4302600; 644400, 4302800; 643400, 4302800; 642600, 4303500; 
642800, 4304000; 643500, 4304400; 644000, 4304700; 644000, 4306700; 
642400, 4306700; 642800, 4306900; 643600, 4307100; 643900, 4307100; 
644100, 4307100; 644100, 4307000; 644500, 4307000; 644800, 4306800; 
645000, 4306800; 645400, 4307100; 645500, 4307100; 645500, 4307300; 
645500, 4308300; 643900, 4308300; 643900, 4307400; 643700, 4307400; 
643300, 4308900; 643100, 4308400; 642800, 4308100; 642600, 4307500; 
642300, 4307400; 642000, 4307000; 641500, 4307000; 641500, 4307600; 
642300, 4307600; 642300, 4308200; 641500, 4308300; 641400, 4310400; 
640500, 4310400; 640600, 4306700; 640600, 4306200; 640200, 4306000; 
640000, 4306100; 639900, 4306300; 639900, 4306700; 639300, 4306700; 
638700, 4306300; 638300, 4306300; 638100, 4307000; 638000, 4307100; 
637500, 4307100; 637500, 4308400; 638800, 4308400; 639000, 4309700; 
639300, 4309700; 639300, 4310500; 639800, 4310500; 639900, 4310300; 
640500, 4310700; 640500, 4311000; 640900, 4311000; 641100, 4311700; 
642000, 4311700; 642300, 4311000; 642200, 4310800; 642200, 4310500; 
643200, 4310800; 643700, 4310500; 644100, 4311100; 644900, 4311100; 
645100, 4310900; 645400, 4310900; 645700, 4310600; 645800, 4310700; 
645800, 4311300; 646400, 4311900; 646800, 4311900; 646800, 4313700; 
647300, 4314200; 648500, 4314200; 648000, 4313200; 648000, 4310000; 
649000, 4309800; 649100, 4309200; 647400, 4309200; 647200, 4308900; 
646900, 4308900; 646700, 4308600; 646300, 4308600; 646300, 4308520; 
646300, 4308300; 646500, 4308100; 646700, 4307900; 647000, 4307900; 
647000, 4308100; 647100, 4308400; 648000, 4308400; 648200, 4308300; 
648200, 4307600; 648600, 4307600; 648600, 4307200; 648800, 4307200; 
648800, 4306800; 648400, 4306800; 648300, 4307100; 647100, 4307100; 
647100, 4307400; 646900, 4307600; 646400, 4308000; 646400, 4307100; 
646600, 4307100; 646600, 4306500; 646400, 4306500; 646200, 4306500; 
646200, 4306000; 644800, 4306000; 644700, 4305900; 644700, 4305400; 
645500, 4305400; 645600, 4305100; 646200, 4305100; 646400, 4304700; 
647000, 4304700; 647200, 4304400; 647700, 4304500; 648700, 4304200; 
648800, 4304600; 648800, 4304800; 649200, 4305300; 649500, 4305300; 
649700, 4305600; 650300, 4305700; 650600, 4305100; 650800, 4304800; 
650800, 4304300; 651700, 4304200; 651700, 4303600; 653100, 4303600; 
654200, 4303200; 654200, 4303500; 654900, 4304200; 655600, 4304200; 
657900, 4305100; 658500, 4304600; 659200, 4304400; 659200, 4304100; 
658800, 4303900; 657800, 4303900; 657100, 4303200; 656700, 4303200; 
656700, 4303800; 656600, 4303800; 656100, 4303600; 655200, 4303000; 
655000, 4303200; 654700, 4303000; 654500, 4302700; 652500, 4302700; 
652400, 4302600; 652700, 4302100; 652900, 4301500; 653300, 4301800; 
653300, 4302400; 653600, 4302400; 653900, 4302000; 654400, 4302300; 
654700, 4302100; 654600, 4301900; 654400, 4301400; 654500, 4300800; 
654700, 4300800; 654500, 4300500; 654300, 4300500; 654100, 4300700; 
653800, 4301300; 653500, 4301100; 653900, 4300600; 653900, 4300300; 
653200, 4299800; 652900, 4300000; 653000, 4301100; 652600, 4301200; 
652100, 4301000; 651700, 4300800; 651700, 4300300; 651100, 4299700; 
651100, 4299200; 650800, 4298900; 648900, 4298800; 649200, 4298100; 
649600, 4298100; 649700, 4297900; 649100, 4297300; 649000, 4297100; 
648800, 4297100; 648300, 4296900; 647800, 4296400; 647600, 4296000; 
647000, 4296000; 647100, 4295600; 647500, 4295400; 647500, 4295100; 
647200, 4295000; 646900, 4294300; 646500, 4294300; 646600, 4295100; 
646800, 4295200; 646800, 4295700; 646500, 4295700; 646300, 4296500; 
647600, 4296500; 647600, 4297100; 648500, 4297700; 648500, 4297900; 
647600, 4297900; 647600, 4299300; 646400, 4299300; 646400, 4297200; 
645800, 4297200; 645800, 4295400; 643800, 4295400; 643200, 4295000; 
642500, 4295000; 642600, 4291900; 642600, 4290400; 642600, 4290000; 
642400, 4289800; 641600, 4289500; 640900, 4289500; 640500, 4289200; 
637500, 4289200; 637500, 4288700; 637400, 4288400; 636700, 4288400; 
636700, 4287800; returning to 636500, 4287700.
    (29) Unit 13: Sacramento County, California.
    (i) From USGS 1:24,000 quadrangle maps Buffalo Creek, Carmichael, 
Elk Grove, Folsom SE and Sloughhouse, California, land bounded by the 
following UTM 10 NAD 83 coordinates (E, N): 650400, 4257200; 650200, 
4257200; 650200, 4258300; 649600, 4258300; 649600, 4257400; 649400, 
4257400; 649400, 4259000; 649100, 4259000; 649100, 4258500; 648500, 
4258500; 648500, 4257400; 648200, 4257400; 648100, 4258300; 647700, 
4258600; 647700, 4258900; 648000, 4259300; 647700, 4259600; 646800, 
4259200; 646500, 4258800; 646500, 4258700; 645800, 4258700; 646100, 
4259000; 646100, 4260000; 646400, 4260100; 646600, 4260400; 646100, 
4260800; 645300, 4261200; 645000, 4260700; 644800, 4260700; 644400, 
4261400; 644400, 4262400; 643800, 4262400; 643600, 4262800; 643200, 
4262800; 643200, 4263300; 643500, 4263300; 643700, 4263200; 643700, 
4263800; 645200, 4263800; 645200, 4262800; 644800, 4262700; 644800, 
4262300; 645300, 4262300; 645300, 4261900; 645000, 4261700; 645300, 
4261500; 645400, 4261700; 646000, 4262100; 645800, 4262400; 646000, 
4262700; 646400, 4262600; 646700, 4262700; 646600, 4263900; 647400, 
4263900; 647600, 4263700; 647800, 4264300; 648100, 4264300; 648300,


[[Continued on page 59983]]