The Allegheny Mountains ( ) are a mountain range situated in the eastern United States. A sub-range of the much vaster Appalachian Mountains, they extend roughly 300 miles (480 km) along a northeast-southwest orientation from north-central Pennsylvania southwestward, through western Maryland and eastern West Virginia. The peaks further continue into portions of Virginia and Tennessee as the Cumberland Mountains—which are essentially part of the same landform—while giving way to the Ridge and Valley Appalachians in the east and northeast.
The Alleghenies comprise a rugged central portion of the Appalachians, rising to at Spruce Mountain in Pendleton County, West Virginia. In the east, they are dominated by a high, steep escarpment known as the Allegheny Front. In the west, they slope down into the closely associated Allegheny Plateau, which extends into portions of Ohio, Kentucky, and Upstate New York. The mountains consist primarily of sandstone and quartzite, the latter of which is extremely resistant to weathering and has allowed the range to maintain much of its height for millions of years. Technically belonging to the Appalachian Plateau province rather than geologically being a "true" mountain range, they have nevertheless been dissected by various watercourses.
Much of the Allegheny Mountains are public lands, most prominently including the Monongahela National Forest, while other tracts are privately owned. Many of these public lands are open to recreation. Their principal settlements are Altoona and Johnstown, Pennsylvania; Cumberland, Maryland; and Elkins, West Virginia. The range has continuously been inhabited by Indigenous groups of Algonquian, Siouan, Iroquoian, and other extractions for millennia. It presented a significant barrier to westward expansion for English colonists—later Americans—which was gradually bridged by various roads, canals, and eventually railroads. The mountains were long dominated by the coal mining and lumber industries, and the regional economy has been detrimentally impacted by their decline.
Ecologically, the Alleghenies are covered by Appalachian mixed mesophytic forests, a type of temperate broadleaf and mixed forest; common trees include sugar maple, beech, tuliptree, basswood, and northern red oak. Among the prevalent fauna are many migratory bird species like wood warblers, vireos, and thrushes. A large number of fish, shellfish, amphibian, and other invertebrate species including hellbenders, lungless salamanders, slugs, leeches, and earthworms are endemic. Common mammals include black bears, white-tailed deer, coyotes, and raccoons. Some of the High Alleghenies contain pockets of Appalachian temperate rainforest, the only true rainforest in eastern North America.
Etymology The name is derived from the Allegheny River, which drains only a small portion of the Alleghenies in west-central Pennsylvania. The meaning of the word, which comes from the Lenape (Delaware) Native Americans, is not definitively known but is usually translated as "fine river". The closest approximation which makes sense is some context from the Jesuit Relations Jesuit Relations, 1632-1673 showing that Alligeh was one of several accepted renderings of the name of the Erie people among the early 17th century missionaries among the Native peoples throughout the eastern Great Lakes region, along with Rique, Yenresh and Erichronon. The suffix -ni means "of the", in Lenape, despite that geh is also Iroquoian for "of the". So, most likely, Alligehni or Oligini would be the Lenape name for the original homeland of the Erie people.
The word "Allegheny" was once commonly used to refer to the whole of what are now called the Appalachian Mountains. John Norton used it (spelled variously) around 1810 to refer to the mountains in Tennessee and Georgia.Norton, Major John (1816), Around the same time, Washington Irving proposed renaming the United States either "Appalachia" or "Alleghania".Stewart, George R. (1967), Names on the Land, Boston. In 1861, Arnold Henry Guyot published the first systematic geologic study of the whole mountain range.Guyot, Arnold, "On the Appalachian Mountain System", American Journal of Science and Arts, Second Series, XXXI, (March 1861), 167-171. His map labeled the range as the "Alleghanies", but his book was titled On the Appalachian Mountain System. As late as 1867, John Muir—in his book A Thousand Mile Walk to the Gulf—used the word "Alleghanies" in referring to the southern Appalachians.
There was no general agreement about the "Appalachians" versus the "Alleghanies" until the late 19th century.
Geography
Extent From northeast to southwest, the Allegheny Mountains run about . From west to east, at their widest, they are about . When combining the Allegheny Province with the Kanawa Province, they run .
The USGS physiographic classification of all land in the United States lists the Allegheny Mountains as a section within the larger Appalachian Plateau province. It may be generally defined to the south by the Allegheny Front, and to the east by the Susquehanna River valley. To the west, the Alleghenies grade down into the dissected Allegheny Plateau. The westernmost ridges are considered to be the Laurel Highlands and Chestnut Ridge in Pennsylvania, and Laurel Mountain and Rich Mountain in West Virginia.
Big Stone Ridge marks the southern extent of the Alleghenies and is an outlier of Flat Top Mountain, with the Tug Fork river running along its western flank. The land to the south and to the west of the Alleghenies is the Valley and Ridge physiographic province.
Allegheny Front and 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 great escarpment roughly follows a portion of the Eastern Continental Divide in this area. Several gorges and valleys drain the Alleghenies: to the east, Smoke Hole Canyon (South Branch Potomac River), and to the west the New River Gorge and the Blackwater and Cheat Canyons. Thus, about half the precipitation falling on the Alleghenies makes its way west to the Mississippi and half goes east to Chesapeake Bay and the Atlantic seaboard.
The highest ridges of the Alleghenies are just west of the Front, with an east/west elevational change of up to . Absolute elevations of the Allegheny Highlands reach nearly , with the highest elevations in the southern part of the range. The highest point in the Allegheny Mountains is Spruce Knob (), on Spruce Mountain in West Virginia. Other notable Allegheny highpoints include Thorny Flat on Cheat Mountain (), Bald Knob on Back Allegheny Mountain (), and Mount Porte Crayon (), all in West Virginia; Dans Mountain () in Maryland, Backbone Mountain (), the highest point in Maryland; Mount Davis (), the highest point in Pennsylvania, and the second highest, Blue Knob ().
Development The Alleghenies contain relatively few large urban centers. The four most populous cities in the region are, in descending order, Altoona, State College, and Johnstown in Pennsylvania, and Cumberland in Maryland.
In the 1970s and 1980s, the Interstate Highway System was extended into the northern portion of the Alleghenies. The region is now served by a network of federal expressways—Interstates 80, 70/76 and 68. Interstate 64 traverses the southern extremity of the range, but the Central Alleghenies (the "High Alleghenies" of eastern West Virginia) have posed challenges for highway planners owing to the region's rugged terrain and environmental sensitivities (see Corridor H). The central Alleghenies continue to rely on a limited network of secondary highways, and the region maintains a lower population density compared to adjacent areas.
In the telecommunications field, a unique impediment to development in the central Allegheny region is the United States National Radio Quiet Zone (NRQZ), a large rectangle of land—about —that straddles the border area of Virginia and West Virginia. Created in 1958 by the Federal Communications Commission, the NRQZ restricts all omnidirectional and high-power radio transmissions, although cell phone service is allowed throughout much of the area.
Protected areas Much of the Monongahela (West Virginia), George Washington (West Virginia, Virginia) and Jefferson (Virginia) National Forests lie within the Allegheny Mountains. The Alleghenies 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.Rosier, George L., Compiler, Hiking Guide to the Allegheny Trail, Second edition, West Virginia Scenic Trails Association, Kingwood, W. Va., 1990.
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 Appalachian 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.
Mineral springs in the High Alleghenies attracted Native Americans and 18th century white settlers and provided a modest incentive to the local economy. The spas developing around these geological features include celebrated resorts that continue to cater to an exclusive clientele, such as The Greenbrier (White Sulphur Springs, West Virginia; hotel built 1858) and The Homestead (Hot Springs, Virginia; original lodge built 1766).
Ecology
Flora The High Alleghenies are noted for their forests of red spruce, balsam fir, and mountain ash, trees typically found much farther north. Hardwood forests also include yellow birch (whose specific name Betula alleghaniensis refer to the mountain range), sugar and red maple, eastern hemlock, and black cherry. American beech, pine, oak, and hickory can also be found. Chestnut trees used to be dominant throughout the Alleghenies. In some areas, it made up as much as 25 to 50 percent of the canopy, now they are found as stump sprouts as a result of blight. The forests of the entire region are now almost all second- or third-growth forests, the original trees having been removed in the late 19th and (in West Virginia) early 20th centuries. The wild onion known as the ramp (Allium tricoccum) is also present in the deeper forests.
Certain isolated areas in the High Alleghenies are well known for their open expanses of sphagnum bogs and heath shrubs (e.g., Dolly Sods, Cranberry Glades). Many plant communities are indeed similar to those of sea-level eastern Canada. But the ecosystems within the Alleghenies are remarkably varied. In recent decades, the many stages of ecologic succession throughout the area have made the region one of enduring interest to botanists.
Fauna