1900. Otsego County Chamber of Commerce, Coon, George, Michigan, Department of Conservation, Michigan State College. Conservation Institute, Otsego County Road Commission, and Otsego Land Use Planning Committee. Extent: 1 map Notes: Map shows both Au Sable State Forest and Pigeon River State Forest, as compared to (presumed) earlier version showing Pigeon... Otsego County Chamber of Commerce, Inc.