From Ohio History Central
Appalachian Zones of the US - USGS
The southeastern portion of Ohio is characterized by hilly topography and considerable relief in some areas, in contrast to the western portion of the state. This area belongs to the physiographic province known as the Appalachian Plateaus, sometimes informally called the Appalachian Uplands or the foothills of the Appalachian Mountains. The area is underlain by bedrock of Mississippian, Pennsylvanian, and Permian ages and, except along its western edge and in northeastern Ohio, was not glaciated during the Pleistocene Ice Age. Thick, erosion-resistant sandstone beds cap many of the hills. These rocks dip gently to the east.