with diverging ridges the level regions on its flanks, it has been figuratively termed the backbone of the northern continent.
The Rocky Mountains do not present a range of uniform elevation, but rather groups and occasionally detached peaks. Though some of these rise to the region of perpetual snows, and are upward of eleven thousand feet in real altitude, yet their height from their immediate basis is not so great as might be imagined, as they swell up from elevated plains, several thousand feet above the level of the ocean. These plains are often of a desolate sterility; mere sandy wastes, formed of the detritus of the granite heights, destitute of trees and herbage, scorched by the ardent and reflected rays of the summer's sun, and in winter swept by chilling blasts from the snow-clad mountains. Such is a great part of that vast region extending north and south along the mountains, several hundred miles in width, which has not improperly been termed the Great American Desert. It is a region that almost discourages all hope of cultivation, and can only be traversed with safety by keeping near the streams which intersect it. Extensive plains likewise occur among the higher regions of the mountains, of considerable fertility. Indeed, these lofty plats of table-land seem to form a peculiar feature in the American continents. Some occur among the Cordilleras of the Andes, where cities and towns and cultivated farms are to be seen eight thousand feet above the level of the sea.
The Rocky Mountains, as we have already observed, occur sometimes singly or in groups, and occasionally in collateral ridges. Between these are deep valleys, with small streams winding through them, which find their way into the lower plains, augmenting as they proceed, and ultimately discharging themselves into those vast rivers which traverse the prairies like great arteries and drain the continent.
While the granitic summits of the Rocky Mountains are bleak and bare, many of the inferior ridges are scantily clothed with scrubbed pines, oaks, cedar, and furze. Various parts of the mountains also bear traces of volcanic action. Some of the interior valleys are strewed with scoria and broken stones, evidently of volcanic origin; the surrounding rocks bear the like character, and vestiges of extinguished craters are to be seen on the elevated heights.
We have already noticed the superstitious feelings with which the Indians regard the Black Hills; but this immense
