Appalachians, ap-pa-la'chi-ans, the old mountain system of eastern North America, extending from Newfoundland to Alabama, a distance of 1,300 miles. It is an old system, far older than the Rocky Mountains, and so worn by frost, air, and water that many of the original lofty ridges are now but rolling crests, bounding wide fertile valleys. The only distinct peaks left are the White Mountains of New Hampshire and the Black Mountains of North Carolina. The highest peak in the north is Mount Washington, New Hampshire, 6,279 feet; the highest peak in the south is Mount Mitchell, North Carolina, 6,711 feet. The central part, particularly the ranges of Pennsylvania and Virginia, is known as the Alleghany Mountains. The eastern fold of the Alleghanies is called the Blue Ridge, from its hazy blue color as seen in the distance by the settlers on the Atlantic coast. Appalachians and Alleghany are Indian names. Other parts of the system are known as the Catskill, the Green, the Smoky, and the Cumberland Mountains respectively. The Adirondack Mountains are a spur of the Labrador-Hudson Bay highlands, not a part of the Appalachians. It is thought, however, that the mountains of Arkansas and Indian Territory are a reappearing spur of the Appalachians. The surface of the entire region may be understood by supposing it to have been at first a low, level plain with rivers running toward the Atlantic. In the process of mountain making we are to understand that this plain rose slowly into gigantic wrinkles two or three miles high, running parallel to the Atlantic coast. The mountain ridges rose so slowly that the rivers were able to keep their course by cutting through the wrinkles crosswise as fast as they were upheaved, for aught we know a fraction of an inch a year. In this way the famous gaps of the Potomac, the Delaware, the Susquehanna, and other crosswise valleys were formed. As stated, the mountain ridges have been worn down to fill up the valleys and to form the Atlantic coastal plain. Enormous swamps in the old plain were filled with vegetation, then covered with earth, and finally upheaved in mountain making, where they now constitute the coal beds of Pennsylvania, Alabama, and other states. See articles on the various states and rivers in this region.