6. The Great Desert, broken by frequent uplifts, and divided by the Humboldt Range.
7. The Sierra-Nevada mountain-system.
8. The basin of the Sacramento River.
9. The mountain-system of the Coast Range.
10. The narrow Pacific slope.
By attending to these distinctions with map in hand we shall gain some adequate idea of the surface of our continent. The first and second of the regions we have left behind us, and at Leavenworth are well out upon the third. It would not be just to call it prairie,—and it is equally distinct from the true Plains. As a grain and grass land, Illinois nowhere rivals it; but its surface is remarkably different from that of the prairies east of the Mississippi. It may be described as an alternation of lofty bluffs and sinuous ravines,—the former known as "divides," the latter as "draws." The top of these divides preserves one general level,—leading naturally to the hypothesis that all the draws are valleys of erosion in a tract of alluvial deposit originally uniform with the plateaus of the divides. Some of the larger draws still serve as the channels of unfailing streams; most of them carry more or less water during the rainy season; few of them are dry all the year round. The river-bottoms which traverse this region are thickly fringed with cotton-wood and elm timber; but it is a rare thing to encounter trees on the top of a divide. The fertility of the soil is boundless. Every species of grass flourishes or may flourish here, with a luxuriance unrivalled on the continent. Of the tract embraced between the Little Blue and the Republican Fork of the Kaw this is especially true. The climate is so mild and uniform that cattle may be kept at pasture the whole year round. Haymaking and the building of barns are works of supererogation. The wild grass cures spontaneously on the ground. To provide shelter against exceptional cases of climatic rigor,—an unusual "cold snap," or a fall of snow which lies more than a day or two,—the ranchero constructs for his cattle a simple corral, or, at most, a rude shed. The utmost complication which can occur in his business is a stampede; and few of our Eastern farmers' boys would hesitate to exchange their scythes, hay-cutters, corn-shellers, and mash-tubs for the saddle of his spirited Indian pony and his three days' hunt after estrays. Over this entire region the cereals thrive splendidly. The wild plum is so abundant and delicious as to suggest the most favorable adaptation to the other stone-fruits. Every vegetable that has been tried in the loam of the river-bottoms succeeds perfectly. There is just reason to think that vine-culture might reach a development along the southern slope of the Republican Bluffs not surpassed in the most favorable positions east of California. We believe it no exaggeration to say that this region needs only culture (and that of the easiest kind) to become the garden of the continent. Its mineral wealth has received scanty examination; yet we know that it contains numerous beds of tertiary coal, and easily worked iron-deposits, in the form both of hydrated oxide and black scale.
On our way through this region we strike the Republican bottom near Lat. 39° 30' N., and Long. 97° 20' W. We are now in the primest part of the buffalo-pasture. As we wind along the base of the steep Republican Bluffs, and the edges of those green amphitheatres made by their alternate approach and retrocession, our whistle scares a picket-line of giant bulls, guarding a divide across the stream, and with tails in air, heads at the down charge, they scour away at a lumbering cow-gallop, to tell the main herd of a progress more resistless than their own. Or, perhaps, our experience of the buffaloes is a more inconvenient one. We may find the main herd crossing our track in their migration from the Republican to the Platte. In such case, there will be a detention of several hours, as the current of a main herd is not fordable by any known human mechanism. The halt will be taken advantage of by timid spectators looking safely out of car-windows,—by bonâ-fide hunters, who want fresh meat, and take along the tidbits of their game to be cooked for them at the next dinner-station,—and by excited pseudo-hunters, who will bang away with their rifles at the defenceless herd, until the ground flows with useless blood, and somebody suggests to them that they might as well call it sportsmanship to fire into a farmer's cow-yard, resting over the top-rail.
Now and then we shall whirl through a village of chattering prairie-dogs, send a hen-turkey rattling off her nest in a thicket on the river's edge, or perhaps surprise even an antelope sufficiently close to point out to the ladies from our window the exquisite flight of that swiftest and most beautiful creature in our American fauna. But our road will not be in running order very long before this sight becomes the rarest of the rare. The stolid buffalo will continue to wear his old paths long after the human presence has driven every antelope into invisible fastnesses.
At intervals along the Republican bottom we shall find ranches springing up under the auspices of our road; immense grain-fields yellowing toward harvest; great herds of domestic cattle grazing haunch-deep through the boundless swales of billowing wild grass; with all the other indications of a prosperous farming settlement, which, keeping pace with the progress of the road, shall eventually become one of the richest agricultural communities in the world, and continuous for over two hundred miles. Here and there we pass a lateral excavation in the face of the bluff where some enterprising settler has opened a tertiary coal-vein, a deposit of iron-ore, or a bed of soft limestone suitable for both flux and mortar purposes. The way-freight trains that meet us now are mainly laden with the wealth of the grazier, the farmer, and the gardener, competing with their brethren of the Upper Mississippi for the markets of St. Louis and New Orleans. Iron-ore, coal, and limestone may form a portion of the cargoes,—but in process of time the mutual vicinity of these minerals will become sufficiently suggestive to induce the erection of smelting-furnaces in situ, and then their combined product will travel the road in the form of pigs.
A little to the westward of a line drawn due south from Fort Kearney to the Republican we shall find a comparatively abrupt and unexplained change taking place in the scenery. Our green river-bottoms will give way to tracts of the color and seemingly of the sterility proper to an ash-heap. Our bluffs will recede, grow higher, and exchange their flat mesa-like surfaces for a curved contour, imitating the mountainous formation on a reduced scale. For long distances the vast gray level around us will be dotted with conical sand-dunes, forever piling up and tearing down as the wind shifts, with a tendency to bestow their gritty compliments in the eyes of passengers occupying windward seats on the train. The lovely blossoms of the running-poppy no longer mat the earth with blots of crimson fire; no more does the sweet breath of eglantine and sensitive-brier float in at the window as we whirl by a sheltered recess of the divides; the countless wild varieties of bean and pea no longer charm us with a rainbow prodigality of pink, blue, scarlet, purple, white, and magenta blossoms. The very trees by the river's brink become puny and stunted; the evergreens begin to replace the deciduous growths; in the shade of dwarfed and desiccated cedars we look vainly for the snowy or azure bells of the three-petalled campanula. Gaunt, staring sunflowers, and humbler compositæ of yellow tinge, stay with us a little longer than those darlings of our earlier scenery; but before we have gone many miles the last conspicuous wave of fresh vegetation breaks hopelessly on a thirsty sand-hill, and we are given over to a wilderness of cacti. Here and there occurs a sightly clump of waxen yellow blossoms, where these vegetable hedgehogs are in their holiday attire,—but it must be confessed that the view is a melancholy change from our recent affluence of beauty. With the other succulent plants, the rich herbage of the prairie has entirely disappeared. There is not a blade of anything which an Eastern grazier would recognize as grass between this boundary and the Rocky Mountains. As we whiz over these wastes at railroad-speed, we shall be apt to pronounce them absolutely sterile. When we stop at the next coaling-station, let us examine the matter more closely. The ground proves to be covered with minute gray spirals of herbage, like a crop of vegetable corkscrews, an inch or two in height, and to all appearance dry as wool. This is the "grama" or "buffalo-grass," and, despite its look of utter desiccation, is highly nutritious. It is almost the entire winter dependence of the buffalo-herds, and domestic cattle soon learn to prefer it to all other feed. Its existence, together with the wide group of changes which we have noticed, denotes that we have passed the threshold of the fourth grand continental division, and are now in the region of the Plains proper.