Allegheny Plateau, dissected plateau, western part of the
Appalachian Mts., extending c.500 mi (800 km) SW from N Pa. to
SW Va., rising to c.4,860 ft (1,480 m) at Spruce Knob, the
highest peak in West Virginia. The E Allegheny Plateau, known as
the Allegheny Mountains or the Alleghenies, has a steep
eastward-facing escarpment often called the Allegheny Front
(c.1,500–1,600 ft/460–490 m high) and is more rugged than the
western portion. The plateau, formed by the folding of
sedimentary rocks, has been subsequently reduced by erosion. The
mountains, rich in coal and timber, also contain iron ore,
petroleum, and natural gas. See more Encyclopedia articles on:
U.S. Physical Geography