OCR Text |
Show io BASIS OP AMERICAN HISTORY [ 1500 Jersey, and the Virginias appears what may be considered the typical formation of the Appalachian system: here is found a relatively narrow plateau from seventy to two hundred miles in width, limited by the Blue Ridge on the east and the Alleghany mountains on the west. ^ The central valley thus contained extends south practically to the termination of the range in the Gulf states, N It is broken here and there by intersecting lines of hills, usually placed longitudinally, which form a great number of minor valleys, but the general character of the great central depression is nowhere lost, arid it early took the significant name of " The Valley." The arrangement of the relief of the continent breaks the lowlands into several belts. Lying between the Cordillera and the Appalachians, and occupying the greater portion of the continent, is the great central basin of North America. Ex, tending as it does from the extreme north to the extreme south, it exhibits wide variations in climate, and hence in superficial character. In the north it is cold and barren; between latitudes fifty and sixty degrees it is covered for the most part with forests; while from fifty degrees southward stretch on the west the dry and treeless great plains and on the east the more fertile prairies. The great plains extend from the base of the Rocky Mountains eastward, and without definite boundary merge irregularly into the prairies of the trans - Mississippi states, and drop off southward |