This eastern desert extends parallel with the Rocky Mountains,—throughout nearly the whole of their length,—from the Rio Grande in Mexico, northward to the Mackenzie River. One tract of it deserves particular mention. It is that known as the llano estacado, or “staked plain,” It lies in North-western Texas, and consists of a barren plateau, of several thousand square miles in extent, the surface of which is raised nearly a thousand feet above the level of the surrounding plains. Geologists have endeavoured to account for this singular formation, but in vain. The table-like elevation of the Llano estacado still remains a puzzle. Its name, however, is easier of explanation. In the days of Spanish supremacy over this part of Prairie-land, caravans frequently journeyed from Santa Fé in New Mexico, to San Antonio in Texas. The most direct route between these two provincial capitals lay across the Llano estacado; but as there were neither mountains nor other landmarks to guide the traveller, he often wandered from the right path,—a mistake that frequently ended in the most terrible suffering from thirst, and very often in the loss of life. To prevent such catastrophes, stakes were set up at such intervals as to be seen from one another, like so many “telegraph posts;” and although these have long since disappeared, the great plain still bears the name, given to it from this circumstance.
Besides the contour of surface, there are other respects in which the desert tracts of North America differ from one another. In their vegetation—if it deserves the name—they are unlike. Some have no vegetation whatever; but exhibit a surface of pure sand, or sand and pebbles; others are covered with a stratum of soda, of snow-white colour, and still others with a layer of common salt, equally white and pure. Many of these salt and soda “prairies”—as the trappers term them—are hundreds of square miles in extent. Again, there are deserts of scoria, of lava, and pumice-stone,—the “cut-rock prairies” of the trappers,—a perfect contrast in colour to the above mentioned. All these are absolutely without vegetation of any sort.
On some of the wastes—those of southern latitudes,—the cactus appears of several species, and also the wild agave, or “pita” plant; but these plants are in reality but emblems of the desert itself. So, also, is the yucca, which thinly stands over many of the great plains, in the south-western part of the desert region,—its stiff, shaggy foliage in no way relieving the sterile landscape, but rather rendering its aspect more horrid and austere.
Again, there are the deserts known as “chapparals,”—extensive jungles of brush and low trees, all of a thorny character; among which the “mezquite” of several species (mimosas and acacias), the “stink-wood” or creosote plant (kaeberlinia), the “grease-bush” (obione canescens), several kinds of prosopis, and now and then, as if to gratify the eye of the tired traveller, the tall flowering spike of the scarlet fouquiera. Further to the north—especially throughout the upper section of the Great Salt Lake territory—are vast tracts, upon which scarce any vegetation appears, except the artemisia plant, and other kindred products of a sterile soil.
Of all the desert tracts upon the North-American continent, perhaps none possesses greater interest for the student of cosmography than that known as the “Great Basin.” It has been so styled from the fact of its possessing a hydrographic system of its own,—lakes and rivers that have no communication with the sea; but whose waters spend themselves within the limits of the desert itself, and are kept in equilibrium by evaporation,—as is the case with many water systems of the continents of the Old World, both in Asia and Africa.
The largest lake of the “Basin” is the “Great Salt Lake,”—of late so celebrated in Mormon story: since near its southern shore the chief city of the “Latter-day Saints” is situated. But there are other large lakes within the limits of the Great Basin, both fresh and saline,—most of them entirely unconnected with the Great Salt Lake, and some of them having a complete system of waters of their own. There are “Utah” and “Humboldt,” “Walker’s” and “Pyramid” lakes, with a long list of others, whose names have been but recently entered upon the map, by the numerous very intelligent explorers employed by the government of the United States.
Large rivers, too, run in all directions through this central desert, some of them falling into the Great Salt Lake, as the “Bear” river, the “Weber,” the “Utah,” from Utah Lake,—upon which the Mormon metropolis stands,—and which stream has been absurdly baptised by these free-living fanatics as the “Jordan?” Other rivers are the “Timpanogos,” emptying into Lake Utah; the “Humboldt,” that runs to the lake of that name; the “Carson” river; besides many of lesser note.
The limits assigned to the Great Basin are tolerably well-defined. Its western rim is the Sierra Nevada, or “snowy range” of California; while the Rocky and Wahsatch mountains are its boundaries on the east. Several cross-ranges, and spurs of ranges, separate it from the system of waters that empty northward into the Columbia River of Oregon; while upon its southern edge there is a more indefinite “divide” between it and the great desert region of the western “Colorado.” Strictly speaking, the desert of the Great Basin might be regarded as only a portion of that vast tract of sterile, and almost treeless soil, which stretches from the Mexican state of Sonora to the upper waters of Oregon; but the deserts of the Colorado on the south, and those of the “forks” of the Columbia on the north, are generally treated as distinct territories; and the Great Basin, with the limits already assigned, is suffered to stand by itself. As a separate country, then, we shall here consider it.
From its name, you might fancy that the Great Basin was a low-lying tract of country. This, however, is far from being the case. On the contrary, nearly all of it is of the nature of an elevated tableland, even its lakes lying several thousand feet above the level of the sea. It is only by its “rim,” of still more elevated mountain ridges, that it can lay claim to be considered as a “basin;” but, indeed, the name—given by the somewhat speculative explorer, Fremont—is not very appropriate, since later investigations show that this rim is in many places neither definite nor regular,—especially on its northern and southern sides, where the “Great Basin” may be said to be badly cracked, and even to have some pieces chipped out of its edge.
Besides the mountain chains that surround it, many others run into and intersect it in all directions. Some are spurs of the main ranges; while others form “sierras”—as the Spaniards term them—distinct in themselves. These sierras are of all shapes and of every altitude,—from the low-lying ridge scarce rising above the plain, to peaks and summits of over ten thousand feet in elevation. Their forms are as varied as their height. Some are round or dome-shaped; others shoot up little turrets or “needles;” and still others mount into the sky in shapeless masses,—as if they had been flung upon the earth, and upon one another, in some struggle of Titans, who have left them lying in chaotic confusion. A very singular mountain form is here observed,—though it is not peculiar to this region, since it is found elsewhere, beyond the limits of the Great Basin, and is also common in many parts of Africa. This is the formation known among the Spaniards as mesas, or “table-mountains,” and by this very name it is distinguished among the colonists of the Cape.