The
Allegheny Mountains are a part of the Appalachian mountain range located in the eastern
United States. They run from northeast to southwest through West Central
Pennsylvania, and the western part of
Maryland and eastern
West Virginia. They begin at the
Allegheny Front, which has an elevational change of up to two thousand feet. Absolute elevations reach well over four thousand feet in West Virginia. The highest point in West Virginia,
Spruce Knob, is located in the Allegheny Mountains on the Allegheny Front.
To the west, the Allegheny Mountains grade down into the dissected
Allegheny Plateau and
Cumberland Plateau. To the east of the Allegheny Mountains (and east of the Allegheny Front) are the
Ridge-and-valley Appalachians.
Much of the
Monongahela National Forest in West Virginia is in the Allegheny Mountains. These mountains also include the
Dolly Sods Wilderness, Laurel Fork Wilderness, and
Cranberry Wilderness.
The bedrock of the Alleghenies is mostly
sandstone and metamorphosed sandstone,
quartzite, which is extremely resistant to weathering. Prominent beds of resistant
conglomerate can be found in some areas, such as the Dolly Sods area. When it weathers, it leaves behind a pure white quartzite gravel. The rock of the Alleghenies were formed during the
Alleghenian orogeny.
Because of intense freeze-thaw cycles in the higher Alleghenies, there is little native bedrock exposed in most areas. The ground surface usually rests on a massive jumble of sandstone rocks, with air space between them, that are gradually moving down-slope. The crest of the Allegheny Front is an exception, where high bluffs are often exposed, exposing an exceptional view.
Cacapon River, Morgan County, West Virginia
Category:Geography of the United States
Category:Mountain ranges of Pennsylvania