The Mammals of Washtenaw County, Michigan

Three natural physiographic divisions cross Washtenaw County from northwest to southeast. The northwestern part of the county is occupied by the rough interlobate moraine of loose-textured soil, the Interlobate Lake District; a broad Clay Morainic Belt occupies most of the central part of the county; and in the southeastern corner of the county is found a low Lake Plain, once the bed of glacial Lake Maumee.

The Interlobate Lake District has a conspicuous system of moraines, making up a most irregular land surface. Steep knolls 100 to 200 feet in height are closely associated with basins, which are often deep, and some of which are occupied by lakes. Small, undrained depressions occur everywhere, producing thousands of acres of swamp and marsh land.