The Allegheny Mountain Range, informally the Alleghenies, is part of the vast Appalachian Mountain Range of the Eastern United States and Canada and posed a significant barrier to land travel in less developed eras. The Allegheny Mountains have a northeast–southwest orientation, running for about 300 miles from north-central Pennsylvania southward, through western Maryland and eastern West Virginia. The Alleghenies comprise the rugged western-central portion of the Appalachians.