The refuge features 8 nature trails encompassing over 10 miles. Nature trails are open to foot traffic only. Please stay on trails, except at special areas where leaving the trail is allowed and indicated by signage. Dogs are allowed on nature trails, but must be on a leash and under control at all times.
Wetland trail
Open Season: Open year-round. Walking only. Not open to biking or horseback riding.
Length: 0.8 miles
Location of trail: Starts from visitor center grounds.
Surface: Compacted gravel, boardwalk.
Difficulty: Light to moderate.
Information: The Wetland nature trail begins at the visitor center, then leads visitors around a semi-permanent marsh that provides year-round habitat for a variety of waterfowl and riparian riparian
Definition of riparian habitat or riparian areas.
Learn more about riparian species. The trail features a boardwalk that leads visitors over the wetland for close-up encounters in this cattail/tule marsh. Listen for the buzzy calls of the marsh wren. Keep a look-out for their basket-like nests hung from the tules in the summer. Benches along the trail provide places to stop and reflect on the sights and sounds of the wetland. The wetland is surrounded by riparian woodland and shallow water habitats as well as upland grasslands. Visitors will see a variety of wildlife species throughout the year.
Upland trail
Open Season: Open year-round. Walking only. Not open to biking or horseback riding.
Length: 0.5 miles
Location of trail: Starts from visitor center grounds.
Surface: Compacted gravel.
Difficulty: Light.
Information: The Upland trail begins at the visitor center, then winds through native grasses and shrubs that provide foraging and nesting opportunities, and shelter for a variety of upland species. Birds such as spotted towhee, California towhee and California quail forage for seeds and hide beneath the native quail brush. Desert cottontail rabbits feed on grasses then take cover hiding from coyotes and birds of prey in the shrubs. Western fence lizards scamper along the ground hunting for insects, and gopher snakes make their way through the brush hunting for rodents. You may find the reptiles coming out earlier in the day to warm themselves on the sand as the morning sun moves higher in the sky.
Chester Marsh trail
Open Season: Open February 15 to September 15. Walking only. Not open to biking or horseback riding.
Length: 1 mile
Location of trail: Accessed from Waterfowl auto tour route.
Surface: Compacted gravel, dirt.
Difficulty: Light to moderate.
Information: The Chester Marsh nature trail is accessed from the Waterfowl auto tour route and is open to visitors from February 15 to September 15. It is closed during the waterfowl hunting season. The trail leads visitors around the Chester Marsh, and alongside riparian woodland and grassland habitats adjacent to the San Joaquin River. About halfway around the trail, visitors may choose a ¼-mile spur that leads them to the San Joaquin River and the remains of a wood and iron truss bridge built in 1884. Travelers on the Merced-Los Banos stage route crossed the river on that bridge to the now-extinct town of Chester.
Sousa Marsh trail
Open Season: Open year-round. Walking only. Not open to biking or horseback riding.
Length: 1 mile
Location of trail: Accessed from the Waterfowl auto tour route.
Surface: Compacted gravel, dirt.
Difficulty: Light to moderate.
Information: The Sousa Marsh trail is accessed from the Waterfowl auto tour route and leads visitors through a riparian woodland to the Sousa Marsh – one of the largest marshes on the San Luis NWR. Once at the marsh, visitors can enjoy a snack or lunch at a picnic table, or view the marsh and its wildlife from atop an elevated observation platform that also provides a spotting scope. Sousa Marsh is a seasonal wetland that supports its largest diversity of waterfowl and other birds during the fall, winter, and spring. Visitors can see large numbers of many duck species and other waterfowl, such as tundra swans. Raptors such as red-tailed hawks and white-tailed kites can be seen coursing back and forth across the marsh watching for an unwary American coot to become a meal. The riparian woodland provides habitat for many migrating songbirds during the fall and spring. Summer resident bird species such as, blue grosbeak and black-headed grosbeak, nest and raise their young in the native trees and shrubs of the woodland, as do year-round residents including the American robin and northern mockingbird.
Winton Marsh trail
Open Season: Open year-round. Walking only. Not open to biking or horseback riding.
Length: 0.5 miles
Location of trail: Accessed from the Waterfowl auto tour route.
Surface: Compacted gravel, dirt.
Difficulty: Light to moderate.
Information: This trail is accessed from the Waterfowl auto tour route. The Winton Marsh is a permanent wetland established in honor of J. Martin Winton, a life-long advocate of wildlife conservation who promoted successful federal wildlife habitat legislation. Winton Marsh’s dense emergent wetland vegetation of cattails and bulrush provides cover and forage for secretive wetland species such as American bitterns, Virginia rail, and sora. In the winter, seasonal raptors such as peregrine falcon are sometimes spotted, perched in the tops of trees along the canal adjacent to a portion of the trail, where they wait patiently – scanning the surrounding grasslands for prey. About one-third of the way along the trail, visitors can peer into the marsh from an elevated observation deck.
Woody Pond trail
Open Season: Open seasonally when West Bear Creek tour route wetlands are flooded (timing may fluctuate annually, but the unit generally is open fall through spring and closed during summer). Walking only. Not open to biking or horseback riding.
Length: 1.75 miles
Location of trail: West Bear Creek Unit along auto tour route.
Surface: Compacted gravel, dirt.
Difficulty: Light to moderate.
Information: The trailhead, accessed from the West Bear Creek auto tour route, features a visitor kiosk and interpretive panels that introduce visitors to the habitats and wildlife of the West Bear Creek Unit. The Woody Pond Nature Trail leads around a densely-wooded seasonal wetland adjacent to the San Joaquin River. The trail makes a loop around the pond with a portion travelling atop the San Joaquin River levee between the river and the pond. The riparian woodland is teeming with bird life during all seasons of the year. As many as 50 species of birds have been seen in just one walk around the trail. If one is lucky, they might even be treated to views of the re-introduced black-tailed deer that use the riparian woods for cover as they move from one foraging area to another. Raptors, songbirds, waterfowl, shorebirds, owls – it is possible to see them all from the Woody Pond trail depending on the season.
Raccoon Marsh trail
Open Season: Open seasonally when West Bear Creek tour route wetlands are flooded (timing may fluctuate annually, but the unit generally is open fall through spring and closed during summer). Walking only. Not open to biking or horseback riding.
Length: 1.3 miles
Location of trail: West Bear Creek Unit along auto tour route.
Surface: Compacted gravel, dirt.
Difficulty: Light to moderate.
Information: The trailhead, shared with the Woody Pond trail, is accessed from the West Bear Creek auto tour route. Raccoon Marsh is a seasonal wetland providing habitat for waterfowl and other wetland species from fall through spring. Mudflats exposed by receding water attract migrating shorebirds in early spring. Long-billed dowitchers, least sandpipers, black-necked stilts, and American avocets are common, but you never know what shorebird surprise might be in store. Habitat like this might host western sandpipers, solitary sandpipers, or short-billed dowitchers. The willows and other shrubs along portions of the trail provide habitat for California quail and towhees, as well as many songbirds and various woodpeckers. Raccoon Marsh in the winter and spring is home to numerous waterfowl species.
Kesterson Unit
Open Season: Open February 15 to September 15. Walking only. Not open to biking or horseback riding.
Length: Entire Kesterson Unit is open to foot traffic.
Location of trail: Kesterson Unit, accessed from main parking lot off CA-140.
Surface: Compacted gravel, dirt, cross-country uplands.
Information: Kesterson is a unit of the San Luis NWR that is open to the general public on a seasonal basis. The unit opens February 15th and closes September 15th, each year. Public access during this period is limited to foot traffic only. The parking lot is located on Highway 140. Kesterson is a unique area containing seasonal wetlands, arid upland grasslands, iodine bush scrub, and vernal pools. Kesterson is also unique in that walking “trails” are outlined by refuge roads, but once inside, visitors are free to roam wherever they choose. Spring is a great time to check the wetland basins for shorebirds. Spring also welcomes the neotropical migrant grassland species that return to the valley to nest, such as western kingbirds and blue grosbeaks. When the winter rains and spring temperatures have been just right, the vernal pools support arrays of beautiful and vibrant uniquely-adapted wildflowers. The invertebrate-rich saline waters of the pools support scores of waterfowl and wading birds. Raptors can usually be seen soaring overhead as they scan the uplands for their rodent prey. Keep your eyes on the ground, too for the habitat is home to black-tailed deer, coyote, jackrabbits, kangaroo rats, fox, and numerous reptiles.