 The County is part of the Au Sable State Forest, specifically the Grayling FMU (Alcona, Crawford, Oscoda, and northern Iosco counties).Glaciers shaped the area, creating a unique regional ecosystem.A large portion of the area is the so-called Grayling outwash plain, which consists of broad outwash plain including sandy ice-disintegration ridges; jack pine barrens, some white pine-red pine forest, and northern hardwood forest.