Appalachian Mountains

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A rainy day in the Great Smoky Mountains, Western North Carolina
A rainy day in the Great Smoky Mountains, Western North Carolina

The Appalachian Mountains are a vast system of North American mountains, partly in Canada, but mostly in the United States, extending as a zone, from 100 to 300 miles wide, running from Newfoundland and Labrador, Canada, 1500 miles south-westward to central Alabama in the United States, although the northernmost mainland portion ends at the Gaspé Peninsula of Quebec. The system is divided into a series of ranges, with the individual mountains averaging around 3000 ft. The highest of the group is Mt. Mitchell in North Carolina (2,040m, 6,684 ft.), which is the highest point in the United States east of the Mississippi River as well as the second highest point in eastern North America.



Appalachian provinces in the US - USGS
Appalachian provinces in the US - USGS
Shaded relief map of Cumberland Plateau and Ridge and Valley Appalachians on the Virginia/West Virginia border
Shaded relief map of Cumberland Plateau and Ridge and Valley Appalachians on the Virginia/West Virginia border
Old fault exposed by roadcut near Harrisburg, Pennsylvania. Such faults are common in the folded Appalachians.
Old fault exposed by roadcut near Harrisburg, Pennsylvania. Such faults are common in the folded Appalachians.

The whole system may be divided into three great sections: the Northern, from Newfoundland to the Hudson river; the Central, from the Hudson Valley to that of New river (Great Kanawha), in Virginia and West Virginia; and the Southern, from New river onwards. The northern section includes the Shickshock Mountains and Notre Dame Range in Quebec, scattered elevations in Maine, the White Mountains and the Green Mountains; the central comprises, besides various minor groups, the Valley Ridges between the Front of the Allegheny Plateau and the Great Appalachian Valley, the New York-New Jersey Highlands and a large portion of the Blue Ridge; and the southern consists of the prolongation of the Blue Ridge, the Unaka Range, and the Valley Ridges adjoining the Cumberland Plateau, with some lesser ranges.

The major ranges comprising the Appalachian system include the Long Range Mountains and Annieopsquotch Mountains in Newfoundland, the Notre Dame Mountains in New Brunswick and Quebec, the Longfellow Mountains in Maine, the White Mountains in New Hampshire, the Green Mountains in Vermont, the Taconic Mountains in New York and Massachusetts, the Berkshire Hills in Massachusetts, the Allegheny Mountains in Pennsylvania, Maryland and West Virginia, the Ridge-and-valley Appalachians in The Poconos Pennsylvania, Maryland, West Virginia and Virginia, and the Blue Ridge Mountains that run from southern Pennsylvania to North Georgia.

The Adirondack Mountains are sometimes considered part of the Appalachian chain but, geologically speaking, are a southern extension of the Laurentian Mountains of Canada.

In addition to the true folded mountains, known as the ridge and valley province, the area of dissected plateau Blue Mountain (Pennsylvania) to the north and west of the mountains is usually grouped with them. This includes the Catskill Mountains of southeastern New York, and the Allegheny Plateau of southwestern New York, western Pennsylvania, eastern Ohio and northern West Virginia. The plateau does not change character but changes name to the Cumberland Plateau in southern West Virginia, eastern Kentucky, western Virginia, eastern Tennessee.

The dissected plateau area is popularly called mountains, especially in eastern Kentucky and West Virginia, and while the ridges are not high, the terrain is extremely rugged. In Ohio and New York, some of the plateau has been glaciated, which has rounded off the sharp ridges, and filled the valleys to some extent. The glaciated regions are usually referred to as hill country rather than mountains.

The Appalachian region is generally considered the geographical dividing line between the eastern seaboard of the United States and the Midwest region of the country. The Eastern Continental Divide follows the Appalachian Mountains from Pennsylvania to Georgia.

Before the French and Indian War, the Appalachian Mountains lay on the indeterminate boundary between Britain's colonies along the Atlantic and French areas centered in the Mississippi basin. After the French and Indian War, the Proclamation of 1763 limited settlement for Great Britain's thirteen original colonies in North America to east of the summit line of the mountains (except in the northern regions where the Great Lakes formed the boundary). This was highly disliked by the colonists and formed one of the grievances which led to the American Revolutionary War.

With the formation of the United States of America, an important first phase of westward expansion in the late 18th century and early 19th century consisted of the migration of European-descended settlers westward across the mountains into the Ohio Valley through the Cumberland Gap and other mountain passes. The Erie Canal, finished in 1825, formed the first route through the Appalachians that was capable of large amounts of commerce.

The Appalachian Trail is a 2,160 mile hiking trail that runs all the way from Mt. Katahdin in Maine to Springer Mountain in Georgia, passing over or past a large part of the Appalachian system.

The chief summits

The Appalachian belt includes, with the ranges enumerated above, the plateaus sloping southward to the Atlantic Ocean in New England, and south-eastward to the border of the coastal plain through the central and southern Atlantic states; and on the north-west, the Allegheny and Cumberland plateaus declining toward the Great Lakes and the interior plains. A remarkable feature of the belt is the longitudinal chain of broad valleys--the Great Appalachian Valley--which, in the southerly sections divides the mountain system into two subequal portions, but in the northernmost lies west of all the ranges possessing typical Appalachian features, and separates them from the Adirondack group. The mountain system has no axis of dominating altitudes, but in every portion the summits rise to rather uniform heights, and, especially in the central section, the various ridges and intermontane valleys have the same trend as the system itself. None of the summits reaches the region of perpetual snow. Mountains of the Long Range in Newfoundland reach heights of nearly 2000 ft. In the Shickshocks the higher summits rise to about 4000 ft. elevation. In Maine four peaks exceed 3000 ft., including Katahdin (5200 ft.), Mount Washington, in the White Mountains (6293 ft.), Adams (5805), Jefferson (5725), Clay (5554), Monroe (5390), Madison (5380), Lafayette (5269); and a number of summits rise above 4000 ft. In the Green Mountains the highest point, Mansfield, is 4364 ft.; Lincoln (4078), Killington (4241), Camel Hump (4088); and a number of other heights exceed 3000 ft. The Catskills are not properly included in the system. The Blue Ridge, rising in southern Pennsylvania and there known as South Mountain, attains in that state elevations of about 2000 ft.; southward to the Potomac its altitudes diminish, but 30 m. beyond again reach 2000 ft. In the Virginia Blue Ridge the following are the highest peaks east of New river: Mount Weather (about 1850 ft.), Mary's Rock (3523), Peaks of Otter (4001 and 3875), Stony Man (4031), Hawks Bill (4066). In Pennsylvania the summits of the Valley Ridges rise generally to about 2000 ft., and in Maryland Eagle Rock and Dans Rock are conspicuous points reaching 3162 ft. and 2882 ft. above the sea. On the same side of the Great Valley, south of the Potomac, are the Pinnacle (3007 ft.) and Pidgeon Roost (3400 ft.). In the southern section of the Blue Ridge are Grandfather Mountain (5964 ft.), with three other summits above 5000, and a dozen more above 4000. The Unaka Ranges (including the Black and Smoky Mountains) have eighteen peaks higher than 5000 ft., and eight surpassing 6000 ft. In the Black Mountains, Mitchell (the culminating point of the whole system) attains an altitude of 6711 ft., Balsam Cone, 6645, Black Brothers, 6690, and 6620, and Hallback, 6403. In the Smoky Mountains we have Clingman's Peak (6611), Guyot (6636), Alexander (6447), Leconte (6612), Curtis (6588), with several others above 6000 and many higher than 5000.

In spite of the existence of the Great Appalachian Valley, the master streams are transverse to the axis of the system. The main watershed follows a tortuous course which crosses the mountainous belt just north of New river in Virginia; south of this the rivers head in the Blue Ridge, cross the higher Unakas, receive important tributaries from the Great Valley, and traversing the Cumberland Plateau in spreading gorges, escape by way of the Cumberland and Tennessee rivers to the Ohio and Mississippi, and thus to the Gulf of Mexico; in the central section the rivers, rising in or beyond the Valley Ridges, flow through great gorges (water gaps) to the Great Valley, and by south-easterly courses across the Blue Ridge to tidal estuaries penetrating the coastal plain; in the northern section the water-parting lies on the inland side of the mountainous belt, the main lines of drainage running from north to south.


Main article: Geology of the Appalachians

The Appalachians are old mountains. A look at rocks exposed in today's Appalachian mountains reveals elongated belts of folded and thrust faulted marine sedimentary rocks, volcanic rocks and slivers of ancient ocean floor, which provides strong evidence that these rocks were deformed during plate collision. The birth of the Appalachian ranges, some 680 million years ago, marks the first of several mountain building plate collisions that culminated in the construction of the supercontinent Pangea with the Appalachians near the center. Because North America and Africa were connected, the Appalachians form part of the same mountain chain as the Atlas mountains in Morocco.

Simplified geology map of the Appalachian Mountains.(by Harold Williams, Memorial University of Newfoundland)
Simplified geology map of the Appalachian Mountains.
(by Harold Williams, Memorial University of Newfoundland)

During the middle Ordovician Period (about 495-440 million years ago), a change in plate motions set the stage for the first Paleozoic mountain building event (Taconic orogeny) in North America. The once-quiet Appalachian passive margin changed to a very active plate boundary when a neighboring oceanic plate, the Iapetus, collided with and began sinking beneath the North American craton. With the birth of this new subduction zone, the early Appalachians were born. Along the continental margin, volcanoes grew, coincident with the initiation of subduction. Thrust faulting uplifted and warped older sedimentary rock laid down on the passive margin. As mountains rose, erosion began to wear them down. Streams carried rock debris downslope to be deposited in nearby lowlands. The Taconic Orogeny was just the first of a series of mountain building plate collisions that contributed to the formation of the Appalachians (see Appalachian orogeny).

By the end of the Mesozoic era, the Appalachian Mountains had been eroded to an almost flat plain. It was not until the region was uplifted during the Cenozoic Era that the distinctive topography of the present formed. Uplift rejuvenated the streams, which rapidly responded by cutting downward into the ancient bedrock. Some streams flowed along weak layers that define the folds and faults created many millions of years earlier. Other streams downcut so rapidly that they cut right across the resistant folded rocks of the mountain core, carving canyons across rock layers and geologic structures.

The Appalachian Mountains contain major deposits of Anthracite coal as well as Bituminous coal. In the folded mountains the coal is in metamorphosed form as anthracite represented by the Coal Region of northeastern Pennsylvania and discovered by Necho Allen. The Bituminous coal fields of western Pennsylvania, southeastern Ohio, eastern Kentucky, and West Virginia is the sedimentary form.

Flora and fauna

Much of the region is covered with forest yielding quantities of valuable timber, especially in Canada and northern New England. The most valuable trees for lumber are spruce, white pine, hemlock, cedar, white birch, ash, maple and basswood; all excepting pine and hemlock and poplar in addition are ground into wood pulp for the manufacture of paper. In the central and southern parts of the belt oak and hickory constitute valuable hard woods, and certain varieties of the former furnish quantities of tan bark. The tulip tree produces a good clear lumber known as white wood or poplar, and is also a source of pulp. In the south both white and yellow pine abounds. Many flowering and fruit-bearing shrubs of the heath family add to the beauty of the mountainous districts, rhododendron and kalmia often forming impenetrable thickets. Bears, mountain lions (pumas), wild cats (lynx) and wolves haunt the more remote fastnesses of the mountains; foxes abound; deer are found in many districts and moose in the north.

Influence on History

For a century the Appalachians were a barrier to the westward expansion of the English colonies; the continuity of the system, the bewildering multiplicity of its succeeding ridges, the tortuous courses and roughness of its transverse passes, a heavy forest and dense undergrowth all conspired to hold the settlers on the seaward-sloping plateaus and coastal plains. Only by way of the Hudson and Mohawk valleys, and round about the southern termination of the system were there easy routes to the interior of the country, and these were long closed by hostile aborigines and jealous French or Spanish colonists. In eastern Pennsylvania the Great Valley was accessible by reason of a broad gateway between the end of South Mountain and the Highlands, and here in the Lebanon Valley settled German Moravians, whose descendants even now retain the peculiar patois known as "Pennsylvania Dutch." These were late comers to the New World forced to the frontier to find unclaimed lands. With their followers of both German and Scotch-Irish origin, they worked their way southward and soon occupied all of the Virginia Valley and the upper reaches of the Great Valley tributaries of the Tennessee. By 1755 the obstacle to westward expansion had been thus reduced by half; outposts of the English colonists had penetrated the Allegheny and Cumberland plateaus, threatening French monopoly in the transmontane region, and a conflict became inevitable. Making common cause against the French to determine the control of the Ohio valley, the unsuspected strength of the colonists was revealed, and the successful ending of the French and Indian War extended England's territory to the Mississippi. To this strength the geographic isolation enforced by the Appalachian mountains had been a prime contributor. The confinement of the colonies between an ocean and a mountain wall led to the fullest occupation of the coastal border of the continent, which was possible under existing conditions of agriculture, conducing to a community of purpose, a political and commercial solidarity, which would not otherwise have been developed. As early as 1700 it was possible to ride from Portland, Maine, to southern Virginia, sleeping each night at some considerable village. In contrast to this complete industrial occupation, the French territory was held by a small and very scattered population, its extent and openness adding materially to the difficulties of a disputed tenure. Bearing the brunt of this contest as they did, the colonies were undergoing preparation for the subsequent struggle with the home government. Unsupported by shipping, the American armies fought toward the sea with the mountains at their back protecting them against Indians leagued with the British. The few settlements beyond the Great Valley were free for self-defence because debarred from general participation in the conflict by reason of their position.

See also


  • Topographic maps and Geologic Folios of the United States Geological Survey
  • Bailey Willis, "The Northern Appalachians," and C. W. Hayes, "The Southern Appalachians," both in National Geographic Monographs, vol. i.
  • chaps, iii., iv. and v. of Miss E. C. Semple's American History and its Geographic Conditions (Boston, 1903).
  • This article incorporates text from the 1911 Encyclopædia Britannica, which is in the public domain.

Further reading

  • Weidensaul, Scott.; 2000, Mountains of the Heart: A Natural History of the Appalachians, Fulcrum Publishing, 288 pages, ISBN 1555911390
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