Dictionary - Definition of Allegheny Mountains

Allegheny Mountains

Allegheny Mountains
Range
Spruce Knob
Country	United States
States	Pennsylvania, Maryland, West Virginia, Virginia

Part of	Ridge-and-valley Appalachians
Borders on	Cumberland Mountains

Highest point	Spruce Knob
- elevation	4,863 ft (1,482 m)
- coordinates	38°41′59″N 79°31′58″W / 38.69972, -79.53278

Geology	Sandstone, Quartzite
Orogeny	Alleghenian orogeny

Map showing the Allegheny Mountains.

The Allegheny Mountain Range (also spelled Alleghany and Allegany) — informally, the Alleghenies — is part of the vast Appalachian Mountain Range of the eastern United States and Canada. It has a northeast-southwest orientation and runs for over 500 miles (800 km) from north-central Pennsylvania, through western Maryland and eastern West Virginia, to southwestern Virginia.

Name

The name derives from the Allegheny River. The meaning of the word, which comes from the Lenape (Delaware) Indians, is not definitively known, but is usually translated as "fine river". A Lenape legend tells of an ancient tribe called the "Allegewi" who lived on the river and were defeated by the Lenape (Stewart, 1967). Allegheny is the French spelling, such as the Allegheny River, which was once part of New France, and Allegany is the English spelling, as in Allegany County, Maryland, a former British Colony.

The word "Allegheny" was once commonly used to refer to the whole of the Appalachian Mountains. John Norton used it (spelled variously) around 1810 to refer to the mountains in Tennessee and Georgia. John Muir, in his book A Thousand Mile Walk to the Gulf (written in 1867), used the word "Alleghanies" for the southern Appalachians. Other people used the word "Appalachians". There was no general agreement until the late 19th century. In the 1860s, Arnold Henry Guyot published the first systematic geologic study of the whole mountain range. His map labeled the range as the "Alleghanies", but his book was titled On the Appalachian Mountain System. The term "Appalachian" became commonly used for the whole range, first by geologists and eventually, everyone (Stewart, 1967).

Geography

See also: List of Mountains of the Alleghenies

Extent

From northeast to southwest, the Allegheny Mountains run about 500 miles (800 km). From west to east, at their widest, they are about 100 miles (160 km). They are defined to the east by the Great Valley (locally called the Cumberland Valley in Pennsylvania and the Shenandoah Valley in Virginia); to the north by the Susquehanna River valley; and to the south by the New River valley. To the west, the Alleghenies grade down into the dissected Allegheny Plateau (of which they are sometimes considered to be a part). The westernmost ridges are the Laurel and Chestnut Ridges in Pennsylvania and Laurel and Rich Mountains in West Virginia.

The mountains to the south of the Alleghenies -- the Appalachians in westernmost Virginia, eastern Kentucky, and eastern Tennessee -- are the Cumberlands. The Alleghenies and the Cumberlands both constitute part of the Ridge and Valley Province of the Appalachians.

The Allegheny Front and the “Allegheny Highlands”

The eastern edge of the Alleghenies is marked by the Allegheny Front, which is also sometimes considered the eastern terminus of the Allegheny Plateau. This represents a portion of the Eastern Continental Divide in this area. The highest ridges are just west of the Front, which has an east/west elevational change of up to 3,000 feet. Absolute elevations of the Allegheny Highlands reach nearly 5,000 feet, with the highest elevations in the southern part of the range. The highest point in the Allegheny Mountains is Spruce Knob (4,863 ft/1,482 m), on Spruce Mountain in West Virginia. Other notable Allegheny highpoints include Thorny Flat on Cheat Mountain (4,848 ft/1478 m), Bald Knob on Back Allegheny Mountain (4,842 ft/1476 m), and Mount Porte Crayon (4,770 ft/1,454 m), all in West Virginia; Dans Mountain (2,898 ft/883m) in Maryland, Backbone Mountain (3360 ft/1024 m), the highest point in Maryland; Mount Davis (3,213 ft/979 m), the highest point in Pennsylvania, and the second highest, Blue Knob (3,146 ft/959 m).

The Alleghenies are drained by a number of gorges, principally the North Branch of the Potomac River and the New River.

Development

There are very few sizable cities in the Alleghenies. The four largest are (in order of population): Altoona, State College, Johnstown (all in Pennsylvania) and Cumberland (in Maryland).

Protected areas

Much of the Monongahela (West Virginia), George Washington (West Virginia, Virginia) and Jefferson (Virginia) National Forests lie within the Allegheny Mountains. These mountains also include a number of federally-designated wilderness areas, such as the Dolly Sods Wilderness, Laurel Fork Wilderness, and Cranberry Wilderness in West Virginia.

The mostly completed Allegheny Trail, a project of the West Virginia Scenic Trails Association since 1975, runs the length of the range within West Virginia. The northern terminus is at the Mason-Dixon Line and the southern is at the West Virginia-Virginia border on Peters Mountain.

Geology

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. When it weathers, it leaves behind a pure white quartzite gravel. The rock layers 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, revealing an exceptional view.

Flora and fauna

^{This section requires expansion.}

The Alleghenies of West Virginia are noted for their forests of red spruce, balsam fir, and mountain ash, trees typically found much farther north.

History