Refuge Units

Strong Unit Sunrise Photo_credit_Tom_Kachelmeyer

The Detroit River International Wildlife Refuge is the only International Wildlife Refuge in North America.  The refuge includes islands, coastal wetlands, marshes, shoals, and waterfront lands along 48 miles of Detroit River and Western Lake Erie shorelines.  

  • Mud Island

    Trees along a lake shore

    The 21-acre Mud Island is the northernmost unit in the Refuge. The island is made of dredge material contained by a surrounding dike. A forest of red maple, silver maple, green ash, cottonwood and willow naturally developed — creating stopover habitat for neotropical migrant birds during spring and fall. Warbling vireos are heard in the breeding season singing from the tops of the cottonwoods.

    Surrounding the island are shallow shoals averaging two feet in depth. These shoals are important habitat for spawning fish. Between the mainland (City of Ecorse) and the island is the Ecorse Channel – a popular fishing location for local residents. The aquatic plants there are diverse, and dabbling ducks and swans are often seen feeding on them. A shipping channel east of the island contains an expansive wild celery bed mid-stream that connects to Grassy Island. These wild celery beds are full of fish and animal life.

    Mud Island is closed to the public.

  • Grassy Island

    Aerial photo of Grassy Island

    The 72-acre Grassy Island is constructed of contaminated dredge material surrounded by dikes. The Refuge also manages shallow shoals nearby, including the site of the former Mamajuda Island. Mamajuda Island was submerged in the 1960's with higher water levels. Prior to that, the island housed a lighthouse and residents from 1849 until 1910, and later a flashing light tower until about the 1950's.

    At least 30 species of fish are found around the Grassy Island shoals, including rock bass, yellow perch, and emerald shiner – many of which also spawn there. Aquatic plants such as muskgrass, pondweeds, and especially wild celery are abundant and provide food for waterfowl. Rocky shallows and fast current create good fish spawning and nursery habitat for species like walleye, which require conditions that keep their eggs well oxygenated.

    The island has naturally become forest and is dominated by cottonwood, box elder, staghorn sumac, and willows with a significant area covered by stands of phragmites. Neotropical migrant birds use the island to feed and rest during spring and fall migration.

    Grassy Island is closed to the public. 

    View additional information about Grassy Island.

    Click to enlarge image.  

  • Calf Island

    The shoreline of Calk Island with trees lining lakeshore

    A naturally formed island in the lower Trenton Channel of the Detroit River, the 11-acre Calf Island provides important stopover habitat for migratory songbirds. The trees and shrubs on the island are often “dripping” with warblers, tanagers, vireos, flycatchers, and other species in spring and fall. Each end of the island is flanked by high quality wild celery beds important for fish and waterfowl. After an interesting past including use by farmers for keeping their calves and a home-site, a forest has naturally developed. Today the ruins of old structures are still visible and lilac bushes used to landscape the property waft their scent on spring breezes. On the north side of the island, a willow lined emergent wetland provides good wildlife habitat. Mature red and swamp white oaks also grow on the island.

    With the exception of hunting, public use activity on the island is prohibited at this time.

    Click to enlarge image. 

  • Gibraltar Bay Unit

    riverside path_Winnie_Chrzanowski_Photo_Credit

    The Gibraltar Bay Unit was once used as a D-51 Nike Missile site. The upland part of the site was decommissioned and seeded with native grasses and wildflowers to benefit pollinating insects. A shoreline habitat project introduced a number of native plants to benefit wildlife. This bay is important for bass, pike, and long-nose gar and is well known for its ice-fishing. 

    Amenities include 1.5 miles of hiking trails, a photo blind, two observation overlooks, and a spotting scope to view wildlife on the bay.The Gibraltar Bay Unit is open to the public daily from dawn to dusk. Location is at 28820 East River Rd, Grosse Ile, Mi.

  • Sugar Island

    A rocky beach at Sugar Island

    Located on the southeast end of Grosse Ile, one mile from Bob-lo Island and 1.5 miles from Amherstburg, Ontario, the 29-acre Sugar Island is fascinating from a cultural and natural history perspective.

    In the 1880's Sugar Island was the site of a major amusement park which included a dancing pavilion, restaurants, boat rental, and even a roller-coaster.

    A diverse forest on the island contains a stand of sugar maples. Migratory songbirds use the forest, but the fall hawk migration is most significant, with large flights of hawks and vultures often seen moving east from directly overhead. Wildlife found at the site includes the state-endangered channel darter, which is found around the island’s quick currents and rocky substrate.

    Migratory songbirds use the forest, and the fall hawk migration is significant, with large flights of hawks and vultures often moving east from directly overhead. The only two significant sand beaches on the Michigan side of the river exist on the east and west sides of the island during years of lower “average” water levels. These beaches are a unique habitat, with threesquare and rufous bulrush growing at the ever-changing water’s edge. Willows, silverweed, milkweeds, and other plants grow in the island’s sandy environment.

    With the exception of hunting, public use activity is only allowed Memorial Day through Labor Day and is limited to the beach on the western side of the island. 

    Learn more about Sugar Island.  

    Click to enlarge image. 

  • Refuge Gateway Property


    The Refuge Gateway property is adjacent to the Refuge's Humbug Marsh Unit in Trenton. This former industrial manufacturing site was home of a Chrysler automotive plant until 1990. The site has been remediated and restored as an ecological buffer for the river and wetlands. The John D. Dingell Jr. Visitor Center and refuge offices are currently under construction at the Refuge Gateway. 

    Today, the land surrounding the Visitor Center is owned by Wayne County and is cooperatively managed with the Refuge. The site has been restored to wetland and upland habitats, and will include a world-class boat dock and fishing pier, greenway trails, and a kayak and canoe launch. Completion of these projects is anticipated in 2020. 

    *The John D. Dingell Jr. Visitor Center is still closed. However the property surrounding the center is open seven days a week during daylight hours.  

    Located at 5437 West Jefferson Avenue, Trenton, MI.

    Learn more about the Refuge Gateway property.  

    Click to enlarge image. 

  • Humbug Marsh Unit


    The 405-acre Humbug Marsh Unit is a key part of the “Conservation Crescent” of the lower Detroit River (which includes the Humbug mainland, Calf Island, Gibraltar Bay, and Sugar Island). Humbug Marsh is a hotspot of biodiversity in this urban landscape. Humbug Marsh was designated as Michigan's first "Wetland of International Importance" by the Ramsar Convention on Wetlands in 2010.  

    Most of the habitat is influenced by poorly drained soils subject to prolonged flooding during wet seasons. There are a few naturally formed higher elevation ridges along the shoreline that create a truly unique landscape. Large oaks exceeding 150 years old are scattered about, with a mosaic of shagbark hickory, ash and elm growing across the unit. Early successional meadow-like habitats are kept open and support plants for polllinators — such as wildflowers, bee balm, mountain mint, ironweed, goldenrods, milkweed — to name a few. The coastal wetlands are dominated by bulrushes, grasses, cattail, phragmites, and sedges. This ever-changing habitat based on Great Lake water levels provide high quality habitat for fish and wildlife.

    The Humbug Marsh Unit is open seven days a week during daylight hours.

    Learn more about the  Humbug Marsh Unit of the Detroit River International Wildlife Refuge. 

  • Gibraltar Wetlands Unit

    Woods at the Gibraltar Wetlands

    This 358-acre unit is near the Gibraltar Carlson High School, only one half-mile from the 405-acre Humbug Marsh Unit and 780-acre Lake Erie Metropark. This complex represents a significant amount of natural area in an urban landscape. Brownstown Creek flows through the unit, fringed by a zone of cattail and phragmites, river bulrush, and blue-joint grass. A small stand of wild rice grows along the shoreline. Stands of mature black walnut and pin oak and large swaths of dogwood and buckthorn shrub create valuable migratory bird habitat. A large wetland mitigation project on the south half of the unit contains emergent wetland, reed-canary grass and a hardwood swamp of green ash, silver maple, cottonwood, and willow. Black-crowned Night Herons, marshbirds, Pied-billed Grebes, and many other species are found here.

    This unit is closed to the general public, but is used by the adjacent high school for outdoor science learning.

    Click to enlarge image. 

  • Lake Erie Metropark

    Marshy area at Lake Erie Metropark

    Lake Erie Metropark is managed in cooperation with the Huron-Clinton Metropolitan Authority. The habitats of the Metropark are a mix of coastal wetlands and early successional forest. The coastal wetland area is one of the largest in western Lake Erie, and is relatively unobstructed by dikes (levees), so that habitats are naturally and seasonally affected by Lake Erie’s water levels. Many different wetland habitat zones can be viewed, each showing different types of vegetation based on elevation. This variation provides habitat for a wide range of fish and wildlife.

    Learn more about Lake Erie Metropark.

    Click to enlarge image. 

  • Strong Unit

    Strong Unit at Sunrise _Tom_Kachelmeyer_Photo_Credit

    This 168-acre unit is highly influenced by Lake Erie water levels, and contains emergent wetland, a former shoreline ridge of swamp white oak trees, and a wet prairie. The large wet prairie is habitat contains blue-joint and reed canary grass, sedge, rose mallow, boneset, swamp milkweed, and other wildflowers. The southern part of the unit is a mix of hardwood swamp and a 17-acre “old field”, or wet prairie which produced soybeans until 2014 and is now fallow.  This prairie has been seeded with native wildflowers and grasses to benefit pollinating insects and other wildlife.  

    There are no hiking trails within the unit; public use is primarily for hunting access. However, in the spring and summer months the parking lot is a great place to watch nesting ospreys on the platform to the south.

    Click to enlarge image. 

  • Brancheau Unit

    Scenic_View_over water at Brancheau Unit_Mike_Grosso_Credit

    The 152-acre Brancheau Unit includes a high quality coastal wetland as well as a 67-acre marsh that was created by two artificial impoundments in 2010. An abundance of Soras, Marsh Wrens, Moorhens, Least Bitterns, Coots and Pied-billed Grebes nest on the unit when habitat conditions are suitable. Migrating Wilson’s Snipes are abundant in September on the mudflat areas, along with many other shorebird species. Fall at the Brancheau Unit can be productive for waterflowl hunters, taking teal, gadwall, wood duck, and mallard. Close to 50-acres of fallowed field were planted with native wildflowers and grasses in 2014.

    Hunting is the only public use activity on the Brancheau Unit allowed at this time.

    Click to enlarge image. 

  • Fix Unit

    Image of fields at the Fix Unit with powerplant in background

    The Fix Unit is mostly former agricultural land which is now fallow and is managed to support waterfowl and shorebirds. A series of water control structures seasonally floods the fields to provide habitat, and also supports flood control along the river. The eastern section of this unit has wet prairie community. The stacks of the Fermi II Nuclear Plant can be seen from the unit.

    The Fix Unit is open to self-guided exploration. Visitors are welcome to hike the dike tops while looking for wildlife. This flat, easy hike is approximately 1.5 miles out and back. 

    Click to enlarge image. 

  • Lagoona Beach Unit

    Image of the Lagoona Beach Nuclear Power Plant stacks from the water

    The Lagoona Beach Unit is managed cooperatively by the U.S. Fish and Wildlife Service in partnership with DTE Energy. The 656-acres of hardwood swamp and coastal wetland habitat is part of an embayed estuary (drowned river mouth), and is influenced by Lake Erie in terms of water level fluctuation, sediment deposition, as well as other natural processes.

    The Lagoona Beach Unit is closed to the public.

    Click to enlarge image. 

  • Ford Marsh Unit

    Wetlands habitat with trees over the water

    Ford Marsh is a 242-acre wetland contiguous to the River Raisin, Lake Erie, and habitat at Sterling State Park – a significantly large wetland complex on the western Lake Erie landscape. Currently dominated by white water lily and approximately 3 feet of water, hundreds of waterfowl have been seen staging here during migration including shovelers, teal, American black ducks, and gadwall.

    Refuge staff can adjust water levels to provide cyclical periods of low and high water levels, which provides optimum habitat diversity for a wide range of wildlife.

    The Ford Marsh Unit is closed to the public.

    Click to enlarge image. 

  • Plum Creek Bay Unit

    Habitat at Plum Creek Bay

    The Plum Creek Bay Unit is influenced by wind events that dictate the amount of water in the bay. Strong west winds blow water out, while east winds flood the bay. Plum Creek flows into this bay at the northwest corner and contains a number of springs on the south side.

    Sora and Virginia Rail are abundant during nesting and migration. Shorebirds such as Least and Semi-palmated Sandpipers, Killdeer, yellowlegs, herons, and egrets are frequently seen in the mudflats and shallows of this unit.

    Hunting is the only public use activity allowed on the Plum Creek Bay Unit.

    Click to enlarge image.  

  • Lady of the Lake Unit

    Winter along a lakeshore wetland with trees and snow

    This 39-acre unit extends along western Lake Erie's shoreline next to the J.R. Whiting Power Plant. The Lake Erie side of the wetland is a bermed trail with a sand beach habitat. Unhardened sand beaches are rare along the western Lake Erie basin. The scarcity of the water/beach interface in this region makes this unit important conservation land. The cooperatively managed wetland is connected to Lake Erie via a 12-inch overflow pipe discharging into the LaPointe Drain Channel and subsequently, Lake Erie with a flap gate to prevent water Lake Erie from entering the wetland.

    The Lady of the Lake Unit is closed to the public.

    Click to enlarge image. 

  • Holloway Unit

    Tundra Swan in wet prairie habitat

    The 48-acre Holloway Unit contains wet prairie and emergent wetland habitat and upland with a mix of shrub and grassland habitat. It is located adjacent to the Erie Marsh and Erie State Game Area.

    The Holloway Unit is closed to the public.

    Click to enlarge image. 

  • Erie Marsh Preserve

    Sunrise over a wet prairie habitat

    This 2,217-acre unit is managed cooperatively with The Nature Conservancy and the adjacent Erie State Game Area. This assemblage of lands is one of the largest contiguous coastal marshes along the western Lake Erie basin, and is very significant in preserving the diversity of the region’s flora and fauna.

    The Erie Marsh Preserve is closed to the public.

    Click to enlarge image. 

  • Gard Island

    Trees along the lake shore at Gard Island

    The 19-acre island is located within North Maumee Bay. The wetlands and forest of Gard Island are cooperatively managed in partnership with the University of Toledo.

    Gard Island is closed to the public.

    Click to enlarge image.