“ Great faults and overthrusts are common, and add to the difficulty of unraveling the structure of the district. In the Appalachian Valley the geological structure is also quite complex, though the strata are not so intensely metamorphosed. The rocks are limestones, shales, and sandstones, and they lie in closed folds that become more open toward the western side of the valley. These folds are peculiar in that their eastward slopes are always steeper than the westward. ”

“ The Blue Ridge, along the eastern side, consists of layers of crystalline rocks, the oldest known in the Appalachians, that have suffered so great an amount of metamorphism as to render the determination of their exact age a matter of considerable difficulty. ”

“ Economic products of considerable importance are found in the Appalachian region. Coal (q.v.) is far the most important; the entire anthracite field and part of the bituminous field of Pennsylvania and other States lie in the Alleghany Mountains and the Cumberland plateau or its northern extension. The petroleum and oil fields of New York, western Pennsylvania, and southward, barely touch the edge of the Appalachian region. ”

“ These medicinal waters, together with the purity and energizing character of the air, has long given the mountains, especially in North Carolina and Virginia, a high repute as a health resort.
Vegetation and Fauna. The Appalachian region is covered with a dense forest growth where it has not been removed by man, forest trees covering the mountain slopes practically to their summits, except where the barren rocks furnish no soil. ”

“ Small game birds and, at the South, wild turkeys are plentiful. Unfortunately, rattlesnakes and copperheads are to be found all over the mountains, yet rarely in dangerous numbers. The woods and streams abound, beyond almost any other part of the Temperate Zone, in fresh-water mollusks. ”

“ At the South, however, the forests retain much of their primeval character and magnificence, some of the trees being of gigantic size. Of the larger mammalia bears, deer, wildcats, are still common, but by no means plentiful. ”

“ Lead has been found in small amounts at many points, but does not occur in sufficient quantity to constitute an independent industry. Copper is found native in the crystalline rocks of Virginia, and as chaleopyrite often in large masses, as at Ducktown, eastern Tennessee. ”

“ These mountain ridges maintain a remarkably uniform altitude, gradually increasing from both directions toward the central mass in western North Carolina. Lying between the comparatively narrow and regular wall of the Blue Ridge and Alleghanian ranges, west of it, is the great Appalachian Valley, which is a characteristic feature of the topography, for it extends the entire length of the mountain system. ”

“ Beginning with the Catskills, the line is broken by the broad valley of the Delaware, but reappears in several prominent ranges in Pennsylvania. The westernmost, or ‘front’ range, is confusingly called First, or Blue Mountain, with Peter's, or Second Mountain, behind it, east of the Susquehanna. East of the Susquehanna, the Tuscarora, Blacklog, Jack's, Standing Stone, and Tussey's are well-defined ranges westward, filling the whole region with crowded heights to the long range distinctively termed Alleghany, which stretches from the border of New York down into West Virginia. ”