The United States territory lying in direct line between the Mississippi River and the Pacific Ocean is now about 1200 miles long from north to south, by 1500 of breadth, in 49° and 32° N. lat., about equal to Equatorial Africa, and 1800 in N. lat. 38°. The great uncultivable belt of plain and mountain region through which the Pacific Railroad must run has a width of 1100 statute miles near the northern boundary; in the central line, 1200; and through the southern, 1000. Humboldt justly ridiculed the "maddest natural philosopher" who compared the American continent to a female figure long, thin, watery, and freezing at the 58th°, the degrees being symbolic of the year at which woman grows old. Such description manifestly will not apply to the 2,000,000 of square miles in this section of the Great Republic she is every where broader than she is long.
The meridian of 105° north longitude (G.)—Fort Laramie lies in 104° 31′ 26″—divides this vast expanse into two nearly equal parts. The eastern half is a basin or river valley rising gradually from the Mississippi to the Black Hills, and the other outlying ranges of the Rocky Mountains. The average elevation near the northern boundary (49°) is 2500 feet, in the middle latitude (38°) 6000 feet, and near the southern extremity (32°), about 4000 feet above sea level. These figures explain the complicated features of its water-shed. The western half is a mountain region whose chains extend, as far as they are known, in a general N. and S. direction.
The 99th meridian (G.)—Fort Kearney lies in 98° 58′ 11″—divides the western half of the Mississippian Valley into two unequal parts.
The eastern portion, from the Missouri to Fort Kearney—400 to 500 miles in breadth—may be called the "Prairie land." It is true that passing westward of the 97 meridian, the mauvaises terres or Bad Grounds, are here and there met with, especially near the 42d parallel, in which latitude they extend farther to the east, and that upward to 99° the land is rarely fit for cultivation, though fair for grazing. Yet along the course of the frequent streams there is valuable soil, and often sufficient wood to support settlements. This territory is still possessed by settled Indians, by semi-nomads, and by powerful tribes of equestrian and wandering savages, mixed with a few white men, who, as might be expected, excel them in cunning and ferocity.
The western portion of the valley, from Fort Kearney to the base of the Rocky Mountains—a breadth of 300 to 400 miles—is emphatically "the desert," sterile and uncultivable, a dreary expanse of wild sage (artemisia) and saleratus. The surface is sandy, gravelly, and pebbly; cactus carduus and aloes abound; grass is found only in the rare river bottoms where the soils of the different strata are mixed, and the few trees along the borders of streams—fertile lines of wadis, which laborious irrigation and coal mining
