The West Virginia. Cyclopedia
The Allegheny Plateau of Ohio, New York, West Virginia, and Pennsylvania is a large province of the northern Appalachian Mountains known for its many ridges, hollows, and lowland valleys. The Pocono Mountains, Allegheny Mountains, and Catskill Mountains are all part of the plateau. Though the term "plateau" is popularly associated with level land, here it refers to a level land that has been weathered into many ridges and valleys. Much of the plateau is drained by the Ohio River and several of its major tributaries, including the Kanawha, Susquehanna, and Monongahela rivers. Part of the plateau in the Poconos is also drained by the Delaware River.