Tobico Marsh was designated as a registered National Natural Landmark in 1976 because of its large size, relatively undisturbed condition and variety of aquatic plant life.

With nearly 2,000 acres (8.1 km2) of wetland woods, wet meadows, cattail marshlands and oak savannah prairies, Tobico Marsh is one of the largest remaining freshwater, coastal wetlands on the Great Lakes.

[1] Comprising 1,652 acres (6.69 km2), the marsh contains three distinct habitats: a wide expanse of open water, an extensive area of marshland, and a mixed hardwood forest.

As logging diminished, the land was sold to several individuals who formed the Tobico Hunting and Fishing Club.

In 1956, Guy Garber and Frank Andersen, the only surviving members, realized the value of the area as a wildlife refuge.