The 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 this urban landscape. Adjacent to the future Refuge Gateway to the north, Humbug is mostly forested with areas that were clear-cut in December 1998. Humbug Marsh was designated as Michigan's first "Wetland of International Importance" by the Ramsar Convention on Wetlands in 2010.
This mesic flatwoods is underlain by poorly drained stiff clay, ponding water for prolonged periods, but with low moisture availability at times. Shagbark hickories, oaks, ash and elm dominate in a mosaicked fashion across the unit with the more aggressive rough-leaved dogwood and goldenrod species present in early successional habitats. The coastal wetland is dominated by bulrushes, native and naturalized grasses, cattail, and Phragmites. An ever-changing habitat condition based on Great Lake water levels, Humbug is a major repository of species and preservation of ecosystem processes.
With the exception of hunting, public use activity on Humbug Island is prohibited at this time. The mainland portion of the unit is open on a semi-regular basis April through October. To view a schedule of open houses and other events at Humbug Marsh and the Refuge Gateway, click here.
Learn more about the Humbug Marsh Unit of the Detroit River International Wildlife Refuge.