Appalachian Mountains

THE APPALACHIAN Mountains of eastern North America comprise a north to south-tending range that extends for 1,600 mi (2,500 km) from the Gaspé Peninsula in Atlantic Maritime CANADA to northern ALABAMA in the UNITED STATES. Uplifted by the collision of continents ancestral to North America and Africa 270 million years ago, the Appalachian Mountains are the oldest mountain range in North America.

The Appalachian Mountains consist of a range of landforms from four physiographic provinces. The New England Province consists of rolling coastal lowlands and rugged interior highlands—like the White Mountains of NEW HAMPSHIRE and MAINE and the Green Mountains of VERMONT—of northern New England and Canada. The Ridge and Valley Province consists of long linear ridges separated by valleys with trellis drainage patterns. The valleys are rich in limestone that dissolves to produce sinkholes and underground caverns, producing KARST topography. The Ridge and Valley Province extends from NEW YORK to Alabama. The Blue Ridge Mountain Province extends from south-central PENNSYLVANIA to northern GEORGIA and is a rugged region of high relief with terrain that ranges from narrow ridges with steep slopes to broad mountains. The Appalachian Plateau (known as the Allegheny Plateau in the north and the Cumberland Plateau in the south) is a well-dissected plateau landscape with deeply eroded, dendritic drainage patterns. The Appalachian Plateau extends from New York to KENTUCKY. The northern Appalachian region from Canada to portions of northern Pennsylvania and NEW JERSEY was glaciated until 10,000 years B.C.E.