Allegheny Mountains

The Allegheny Mountain Range (/ˌælɪˈɡeɪni/ AL-ih-GAY-nee)—also spelled Alleghany or Allegany, less formally the Alleghenies—is part of the vast Appalachian Mountain Range of the Eastern United States and Canada. Historically, it represented a significant barrier to westward land travel and development. The Alleghenies have a northeast–southwest orientation, running for about 300 miles (480 km) from north-central Pennsylvania southward, through western Maryland and eastern West Virginia.

The Alleghenies comprise the rugged western-central portion of the Appalachians. They rise to 4,862 feet (1,482 m) in northeastern 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 Ohio and Kentucky. The principal settlements of the Alleghenies are Altoona, State College, and Johnstown, Pennsylvania; and Cumberland, Maryland.

Using the United States Geological Survey (USGS) classification of physical geography (physiography), the Allegheny Mountain range is part of the Appalachian Plateau province of the Appalachian Highlands physiographic division.

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 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 the irony that geh is also Iroquoian for "of the." So, most likely, Alligehni, or Oligini, would probably 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. Around the same time, Washington Irving proposed renaming the United States either "Appalachia" or "Alleghania". In 1861, 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. 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.

From northeast to southwest, the Allegheny Mountains run about 300 miles (480 km). From west to east, at their widest, they are about 100 miles (160 km). When combining the Allegheny Province with the Kanawa Province, they run 400 miles (640 km).

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.