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.