"The Black Hills have an area of five-thousand square miles of a rudely elliptical form with its major axis, approximately, north-northwest. Most of this area lies within our state. The true limit of the Hills is quite distinctly marked by a sharp ridge of sandstone, three hundred to six hundred feet in relative height, which becomes broader and more plateau-like towards the north and south ends. This ridge is separated from the higher mass of hills within by a valley one to three miles in breadth, which is known as the Red Valley, from its brick-red soil, or the 'race course,' which name was given it by the Indians because of its open and smooth character, affording easy and rapid passage around the Hills. The junction of the outer base of the Hills with the surrounding table lands has an altitude of three thousand, five hundred to four thousand feet. Within this Red Valley one gradually ascends the outer slope of the Hills and soon enters, at an altitude of four thousand five hundred or five thousand feet, the woody portion of the region. This outer slope varies greatly in width and is underlaid by older sedimentary rocks, cut in almost every direction by narrow deep canons. This feature covers nearly the whole of the western half of the Hills proper, where erosion has been less active on account of its distance from the main channels of drainage. Usually, from the broken interior edge of this slope or sedimentary plateau one descends a bluff or escarpment, and enters the central area of slates, granite, and quartzites, which is carved into high ridges and sharp peaks cut by many narrow and deep valleys and ravines and generally thickly timbered with the common pine of the Rocky Mountains. Toward the south, about Harney Peak, the surface is peculiarly rugged and difficult to traverse. Toward the north, also, about Terry and Custer peaks, a smaller rugged surface appears; but in the central area between and extending west of the Harney range is a region which is characterized by open and level parks much lower than the surrounding peaks and ridges."