Detroit River International Wildlife Refuge

While the refuge consists of more than 6,200-acres of habitat, it is not one contiguous plot of land. Made up of more than 30 separate parcels, known as refuge units, each were acquired either through purchase, donation or cooperative agreement. While some refuge units have specific covenants or stipulations about how they are to be managed, all are governed by the National Wildlife Refuge System Improvement Act of 1997.

A brief description of each refuge unit is described in order of location from north to south.

Mud Island Unit

Mud Island is the northernmost island on the refuge and is closed to the public. The 21.15-acre island was donated to the National Wildlife Refuge System in 2001. Approximately 75 % of Mud Island is forested with deciduous hardwood trees and is dominated by red maple, silver maple, white ash, cottonwood and willow trees. These forests create vital stopover habitat for neotropical migrant birds during the spring and fall. Warbling vireos can often be heard in the breeding season from the tops of the cottonwood trees. Bald eagles rest there high in the treetops.

The shallow shoals surrounding the island are two feet deep on average and support a variety of aquatic plant species like wild celery. Between the mainland, city of Ecorse, and the island lies the Ecorse Channel, which is a popular fishing location for waterfowl and local residents alike. The aquatic plants here are diverse and welcome an abundance of foraging dabbling ducks and swans, both tundra and mute. A deep shipping channel exists east of the island with a large wild celery bed midstream that connects to Grassy Island.

Grassy Island / Mamajuda Shoal Unit

Grassy Island, which is closed to the public, is largely constructed of contaminated dredge material, enclosed by dikes and its surrounding waters, Mamajuda Shoal, which are biologically rich. Together, the island and shoal comprise more than 304-acres that were acquired in 1961 to establish the Wyandotte National Wildlife Refuge. At least 30 species of fish are found here including rock bass, yellow perch and emerald shiner. Numerous aquatic plants, including muskgrass, varies pondweed species and wild celery are abundant here. Diverse rock structures and current speeds create beneficial fish spawning and nursery habitat.

Although the soils are contaminated, the uplands of the island are dominated by early successional tree species including: eastern cottonwood, box elder, staghorn sumac, and willow trees. The island also has a heavy infestation of invasive plants. Albeit far from pristine, the island provides vital habitat and has demonstrated high use by neotropical migrant birds during spring and fall.

Refuge Gateway

The Refuge Gateway Unit sits adjacent to the Humbug Marsh Unit in Trenton, Michigan and was added to the refuge in 2013. This 44-acre industrial brownfield was the home of a Chrysler automotive plant until 1990. Today it is mostly owned by Wayne County, with the exception of four acres owned by the U.S. Fish and Wildlife Service where the John D. Dingell Jr. Visitor Center is located. A master plan developed by the refuge, in collaboration with Wayne County, and other vested partners, was adopted for the site to serve as a blueprint for cleanup and restoration work.

The property currently includes the interactive, LEED certified, John D. Dingell Jr. Visitor Center for the Detroit River International Wildlife Refuge, a world-class fishing pier and picnic area. Upcoming additions include a handicap accessible kayak launch and natural playscape. This site connects to the Downriver Linked Greenway Initiative trail system and is readily accessible by car, bus, foot and bicycle.

The Refuge Gateway Unit is open for public visitation Thursday through Sunday during daylight hours.

Humbug Marsh

The 405.16-acre Humbug Marsh Unit is a major part of the conservation crescent of the lower Detroit River - including Humbug mainland, Calf Island, Gibraltar Bay and Sugar Island - and a hotspot of biodiversity in an urban landscape. Sitting south of the Refuge Gateway, Humbug Marsh is mostly forested with some areas that were clear-cut in December 1998. In 2004, the property was purchased by the refuge after a group of local supporters stopped development that would have forever changed the face of the river and surrounding lands. The parcel represents the last mile of undeveloped shoreline along the U.S. mainland of the Detroit River and contains important habitat for many rare fish and wildlife species. Humbug Marsh was designated as Michigan's first Wetland of International Importance in 2010 by the Ramsar Convention on Wetlands.

This wet mesic flatwoods habitat is underlain by poorly drained stiff clay that can hold water for prolonged periods. Shagbark hickory, oak, ash and elm trees dominate the landscape in a mosaicked fashion across the unit with rough-leaved dogwood and goldenrod species present in early successional habitats. The coastal wetland is dominated by bulrushes, native and naturalized grasses, cattail and invasive phragmites. An ever-changing habitat that is dependent on Great Lake water levels, Humbug Marsh is a major repository of species and preservation of ecosystem processes.

Public access varies across the three parts of this unit.

• The Humbug Marsh mainland is split by the Handler Drain. Access is allowed north of the Handler Drain during the same hours as the Refuge Gateway Unit. South of the Handler Drain is closed to public use, with the exception of an archery-only reserved deer hunt in partnership with the Michigan Department of Natural Resources.
• Hunting is the only public use allowed on Humbug Island
• Humbug Wetland is open year-round for all public access, including kayaking, waterfowl hunting and fishing from watercraft. Fishing from the shoreline is not permitted.

Calf Island Unit

A naturally formed island in the lower Trenton Channel, this 11.36-acre island provides important stopover habitat for migratory songbirds. Each end of the island, which was acquired in 2002, is flanked by high-quality wild celery beds that create important habitat for fish and waterfowl. The forest is reflective of a history of intensive farming and development with ruins of old structures, lilac bushes and decades-old debris. On the north side of the island, an emergent wetland is surrounded by willow shrubs. A number of mature red and swamp white oaks also exist on the island. With the exception of hunting, public use activity on the island is prohibited.

Gibraltar Bay Unit

Much of the upland of the Gibraltar Bay Unit was once used as a former D-51 Nike Missile site. The site was home to 30 anti-aircraft Nike Ajax missiles, 12 launchers and two radar towers between 1955 and 1963. The embankment to Gibraltar Bay continues to protect the former launcher area. After the site clean-up was complete in 1998, the unit was restored to grassland habitat. A shoreline habitat project was completed in the mid-2000s introducing a number of native plants. The 40.53-acre property was added to the refuge in 2010.

Water flows through the embayment from the east side of Grosse Ile and supports a diverse community of aquatic plants. You’ll likely see common three-square, arrowhead, pickerelweed, American lotus, pondweeds, wild celery and muskgrass when you visit the area. The variety of plant life in this protected bay is important for multiple bass species, northern pike and long-nose gar. The Gibraltar Bay Unit is open year-round for self-guided exploration.

Sugar Island Unit

Situated on the southeast end of Grosse Ile, just one mile from Boblo Island and one and a half miles from Amherstburg, Ontario, the 28.94-acre Sugar Island is fascinating from a fish and wildlife perspective. The state-endangered channel darter is found around the island’s quick currents and rocky substrate. The only two significant sand beaches on the Michigan side of the international border exist on the east and west side of the island. These beaches are locally unique with common three-square and rufous bulrush at the ever-changing water’s edge. Willow trees, silverweed, milkweed and other native plants can be found in the island’s sandy environment. The forest is particularly diverse, with understories rich in native grasses and sedges, as well as a stand of young sugar maple trees. Sugar Island was added to the refuge in 2011. The western beach of the island is open for public use from Saturday before Memorial Day through Labor Day, otherwise hunting is the only public use allowed.

Gibraltar Wetlands Unit

Acquired in 2008, the 358.58-acre Gibraltar Wetlands Unit is located within a half-mile of the 405-acre Humbug Marsh Unit. A large contiguous block of protected land is rare in an urban area, but even rarer still is the diversity of habitat within this unit. Significant to the local landscape and cultural history of the area, Brownstown Creek flows through the eastern portion of the unit. It’s fringed by river bulrush and dominated by blue-joint grass. Stands of mature black walnut and pin oak trees exist along with large swaths of dogwood and buckthorn shrub. The large wetland mitigation on the south half of the wetlands contains wet reed-canary grass habitat and rich green ash swamp. The Gibraltar Wetlands Unit is situated adjacent to the Gibraltar Carlson High School and is frequently used by the school's wetlands science classes via special use permit. This unit is closed to the public.

Lake Erie Metropark Unit

780-acres of Lake Erie Metropark Unit is managed in cooperation with the Huron-Clinton Metropolitan Authority. With sweeping lake vistas, a golf course, wide open spaces and hiking trails, the park is a popular recreation area. The habitats of the Metropark are a mix of wetlands and early successional forest. In 2006, a cooperative agreement was finalized which added this as a cooperatively managed unit of the refuge.

U.S. Silica Unit

The U.S. Silica Unit is managed cooperatively by the refuge, in partnership with U.S. Silica Holdings. The unit encompasses 95-acres and consists of Great Lakes Marsh and Hardwood Swamp, with water levels influenced by the Huron River, Detroit River and Lake Erie. Navigable waters are open to the public.

Taylor Unit

The Clive and Clarice Taylor Unit was donated to the refuge in 2016 by the late Clive Taylor and his wife, Clarice. The 43-acre property is hydrologically connected to Lake Erie through Mouillee Creek. Mr. Taylor spent years creating wildlife habitat from former agricultural fields that now include 14.5-acres of wetlands, 14 acres of agricultural lands, scenic oak and hickory woodlots and prairie / grassland habitat. The unit attracts an incredible variety of animals including deer, beavers, opossums, coyotes, muskrats, mink, wood ducks, geese, great blue herons, snowy egrets and other waterfowl. The Taylor Unit will eventually be used primarily for environmental education purposes and is currently not open to the public.

Strong Management Unit

Another unit that is highly influenced by Lake Erie water levels, the Strong Unit, contains emergent wetland, a former shoreline ridge of trees and wet meadow communities. Unique to this unit is the abundance of blue-joint grass, shoreline sedge, rose mallow, and swamp milkweed. These meadows are surrounded by willow shrubs, dogwoods, and mature oaks, which collectively create an important diversity of habitat for native species. This unit includes 168 acres in its main tract, nearly 56 acres south of the Estral Beach Dike and six acres across Port Sunlight Road. Self-guided public use, including hunting, is only allowed on the main 168-acre parcel. The protection dike to the south is owned by Estral Beach and walking or crossing on it is prohibited.

Brancheau Management Unit

Brancheau was the first unit purchased for the newly established Detroit River International Wildlife Refuge in 2003. Half of the wetlands at Brancheau are surrounded by dikes, giving refuge staff the ability to control water levels for wildlife within the unit. Brancheau is a safe haven for a variety of bird species, including a high abundance of sora, marsh wrens, common gallinule, American coots and pied-billed grebes that all nest at there. Least bittern can be heard calling here and are periodically seen when they rise above the cattails. This unit is a combination of several tracts that total nearly 224-acres. It consists of roughly 80-acres of diked wetlands, 54-acres in two prairie tracts along Blanchett Street and Strong Road, and another 90-acres of adjacent coastal wetlands outside the dikes that are open to Lake Erie.

A portion of the diked area is open to waterfowl hunting through a drawing with the Michigan Department of Natural Resources and hunters typically take blue and green-winged teal, gadwall, wood duck and mallard. With the exception of hunting, public use of the Brancheau Management Unit is prohibited.

Fix Management Unit

The majority of the nearly 210-acre Fix Management Unit was agricultural fields prior to a habitat restoration project conducted from 2016 to 2017, that restored a portion of the landscape back into wetlands. Today, the unit consists of coastal wetland habitat, a small forest and two diked wetlands that allow refuge staff to manipulate water levels to mimic natural lake level changes. The property was acquired in 2007 and has a rich diversity of wetland plants, as well as a healthy population of prairie cordgrass, a Michigan species of special concern. This unit is adjacent to the Michigan Nature Association Swan Creek Plant Preserve, which includes state-threatened American lotus beds. Self-guided public use is allowed, including hunting on 95-acres of the Fix Management Unit with the Fix and Newport Beach Marina tracts of land, while the Sisung tract remains closed to the public.

Lagoona Beach Unit

The 656.45-acre Lagoona Beach Unit has been managed cooperatively by the refuge in partnership with DTE Energy since 2003 and is closed to the public. This unit, which surrounds the Fermi Nuclear Power Plant, is comprised of wetlands that are dominated by American lotus, cattail and phragmites.

Port of Monroe Unit

The Port of Monroe Unit was donated to the refuge in 2015 by the city of Monroe and the Port of Monroe, which were co-owners of the 34.99-acre parcel. The unit is directly adjacent to Interstate 75 and across from Sterling State Park. The property is mostly coastal wetlands with a hydrological connection to Lake Erie. The Port of Monroe Unit is closed to the public.

Ford Marsh Unit

Ford Marsh became part of the refuge in 2009 and is closed to the public. It is approximately 180 acres of contiguous wetland and 60 acres of uplands adjacent to the mouth of the River Raisin and Lake Erie. This unit is a significantly large wetland within the western Lake Erie landscape, and was once part of the historic Golo Club, which was an early hunt club that boasted General George Custer as a member. Later it was used as a private hunt club for the Ford family. Previously dominated by white water lily, the unit now has water management capabilities that allow it to be managed to mimic a naturally functioning marsh. This has increased the diversity of wetland plants to include American lotus, arrowhead, river bulrush, bur weed and smartweed. Hundreds of waterfowl have been seen including Northern shovelers, blue and green-winged teal, American black ducks and gadwall.

Plum Creek Bay Unit

The 125.74-acre Plum Creek Bay Unit was donated to the refuge in 2008 and is directly influenced by wind events that dictate the amount of water in the bay. West winds blow water out, while east winds flood the bay. Plum Creek flows into this bay in the northwest corner and a number of natural springs flow into the bay on the south side.

Refuge staff have begun treatment of phragmites throughout the unit to promote the many species of native wetland plants found here. Secretive marsh birds like sora and Virginia rail are particularly abundant here during nesting and migration. Shorebirds like least and semipalmated sandpipers, greater and lesser yellowlegs, killdeer and a variety of herons and egrets are frequently seen in the mudflats and shallows of this unit. With the exception of hunting, public use activity on the Plum Creek Bay Unit is prohibited at this time.

Lady of the Lake Unit

The Lady of the Lake Unit was originally under a cooperative management agreement with Consumers Energy, until 2017 when they donated it to the refuge. This unit is 39.5-acres of wetlands and western Lake Erie shoreline situated next to the J.R. Whiting Power Plant. The wetland is connected to Lake Erie via a water control structure structure
Something temporarily or permanently constructed, built, or placed; and constructed of natural or manufactured parts including, but not limited to, a building, shed, cabin, porch, bridge, walkway, stair steps, sign, landing, platform, dock, rack, fence, telecommunication device, antennae, fish cleaning table, satellite dish/mount, or well head.

Learn more about structure on the LaPointe Drain that allows the unit to be actively managed by pumping or left open to allow fish passage fish passage
Fish passage is the ability of fish or other aquatic species to move freely throughout their life to find food, reproduce, and complete their natural migration cycles. Millions of barriers to fish passage across the country are fragmenting habitat and leading to species declines. The U.S. Fish and Wildlife Service's National Fish Passage Program is working to reconnect watersheds to benefit both wildlife and people.

Learn more about fish passage . The Lake Erie side of the wetland is a natural beach ridge with a sand beach worked by wave action on the east side. Unhardened sand beaches are rare along the Western Lake Erie Basin. The scarcity of the water / beach interface in this region reduces erosion and protects important and unique species and ecosystem processes. The Lady of the Lake Unit is closed to the public.

Holloway Unit

The 47.73-acre Holloway Unit was acquired in 2011 and is a slice, in terms of the surrounding landscape, of the Erie Marsh and Erie State Game Area. Much of it is covered in American lotus. The uplands contain a mix of shrub and grassland habitat. The Holloway Unit is closed to the public.

North Maumee Bay Unit

The 199-acres of coastal wetland directly north of Erie Marsh Preserve was donated to the refuge in 2017 by Consumers Energy. The unit is adjacent to our Holloway Unit and just south of the Lady of the Lake parcel. The property is mostly open water, water lily, and American lotus surrounded by various shoreline and islands. The only access to this property is by water. With the exception of hunting, public use activity on the North Maumee property is closed to the public.

Erie Marsh Preserve Unit

A cooperative unit with The Nature Conservancy since 2006, the preserve and adjacent Erie State Game Area is one of the largest contiguous coastal marshes along the western basin and very significant in preserving a vast array of the region’s flora and fauna. The preserve consists of 2,216.63-acres of managed diked wetlands, upland forests and coastal wetlands open to Lake Erie.

The Erie Marsh Preserve is open to the public for general self-guided exploration, except during waterfowl season. The Nature Conservancy has a lease agreement with the Erie Shooting Club, the original owner, for the exclusive rights of use during the state waterfowl season.

Gard Island Unit

Gard Island is managed cooperatively with the University of Toledo and is closed to the public. The 18.80-acre island is located within North Maumee Bay. In 2005 it was added as the southernmost unit of the Detroit River International Wildlife Refuge.