Two hundred miles below this immense field of novelties, we arrive at the mouth of the cañon whence the river has been of late years frequently navigated, by Mackinaw and flat boats, to its union with the Missouri. Of this portion, but little has yet been written except by scientific explorers. For the first eighty miles of the distance, the river, almost a continuous rapid, rolls between gently undulating banks, dotted at intervals with clumps of stunted pines. Frequent ledges of rock jut into the stream, and wherever a bend or projection has served to arrest the flow of debris in time of flood, or catch the detritus washed from the rocks, a little bottom affords sustenance to a dense growth of majestic cottonwoods. This feature is prominent in the river scenery until the stream enters the Bad Lands, four hundred miles below the cañon. These groves, unlike the irregular groves that adorn the Eastern rivers, present to the voyager a straight regular outline on all sides, a feature imparted to them by the beavers, which cut down unsparingly both great and small trees outside the given spaces. This perfect regularity, always at right angles with the upland shore, gives to these frequent groves the appearance of artificial cultivation, and in the very midst of one of the most boundless solitudes in the world, the observer frequently finds himself indulging a thought that there may be some old mediæval castle still standing within the shadow of these trees.
After one has sailed about eighty miles, and finds himself descending an expansive reach of the river, the eye is suddenly attracted by the appearance on the right of an immense and seemingly interminable ridge of yellow rocks, very high, precipitous, and crowned along its summit by a forest of stunted pines. It is several miles distant, and its sheer, vertical sides gleam in the sunlight like massive gold. Far away it stretches, seemingly on an air line beyond the field of vision, presenting few inequalities of surface, and none of the features of ordinary mountain scenery.
The Happy Valley of Rasselas was not more strongly protected against outside intrusions by the precipices surrounding it, than is this portion of the Yellowstone Valley from all access by those who dwell beyond this ridge of sandstone.
At a distance of ten miles or more from where it first appears, the river has worn its way through it. We enter the massive gorge. Higher and higher rise the gleaming cliffs, seemingly straight up from the river’s bed, until sunlight disappears, and the blue sky above you spans like a roof the confronting crags. The illusion vanishes with decreasing height, the gloom painted in darkness upon the frightened stream grows again into sunlight, and for the next few miles you pass through banks of green adorned on either hand with citadels, temples, towers, turrets, spires, and castellated ruins, all deftly wrought by the wind and rain upon the exposed portions of the yellow rock. Neither the Hudson, with its green hills and massive knobs, nor the Columbia, with its crags and beetling cliffs, presents anything at all comparable to this. At one moment you look up at the sheer sides of a temple wrought into a form not unlike that of Edfou or Denderah, except as it surpasses them in its magnificent dimensions, all its sides presenting in the vitrified fractures of the layers of rock, regular rows of seeming hieroglyphics, and its conical, time-worn summit, gray and smooth with the frosts and storms of centuries. A little beyond stand the remains of a castle; and still farther on, seemingly equidistant from each other, three or four stately towers; then comes a massive citadel of stone, with embrasures, walls, and portholes, all the apparent paraphernalia of a mighty fortress.
These scenes, with all the variety that Nature observes in her works, occur at intervals of thirty or forty miles, every time the river penetrates the ridge, for a distance of two hundred miles; and all the way between these passages, on one side or the other of the beautiful stream, you behold stretching along upon the most exact of natural lines the pine-crowned ridge itself, skirted by meadows reaching to the margin. Before quite losing this grand exhibition, the river, fed by Clark’s Fork, the Rosebud, and the Big Horn, changes its character. The waters become dark and turbid, and spread out to more than a mile in width. The valley expands correspondingly, and the foothills and mountains are more distant. About midway of this passage through the yellow sandstone, Pompey’s Pillar, a table of rock separated by the river from the main ridge, stands isolated, towering to a height of several hundred feet over the plain, on the brink opposite. Its summit of less than half an acre, accessible with difficulty on the inland side, according to Captain Clark, affords an extensive view of the surrounding country.
At the mouth of the Big Horn the last view of the Rocky Mountains, which thus far have enlivened the scenery with their varied phenomena of storm and sunlight, fades upon the vision, and your voyage lies for several miles through a richer agricultural region than any you have yet seen. Here are fine meadows covered with bunch-grass, and, upon the distant hills, herds of elks, flocks of mountain sheep, antelopes, and deer. The temptation, often too great to be resisted, makes the hunter forgetful of Crows and Sioux, and sometimes lures him to his death. The rapids now become less frequent, though several of them are more formidable. At one point, where the river passes through the ridge for a distance of six miles, it has no channel of sufficient depth to float an ordinary Mackinaw, and voyagers are obliged by main force to push their boats into the pool below. Captain Clark gave to this obstruction the name of Buffalo Shoals. A few miles below this he saw, in the midst of a formidable rapid, a grizzly bear upon a rock, and gave to the place the name of Bear Rapids.
The early hunters and trappers of the Northwest found no region more favorable for their pursuit than the central valley of the Yellowstone. Here came Ashley, and Bridger, and Culbertson, and Sarpie, as early as 1817. The latter built a fort, which he called Fort Alexander, some remains of which are still standing on the margin of one of the most delightful meadows in the valley.
The last and most fearful rapid of the Yellowstone is near the mouth of the Tongue River, and was named by Captain Clark, Wolf Rapid, because he killed a wolf near it. The river is here lashed into a fury. The roar of the rapid is heard for several miles, and the tossing spray and seething foam can be seen at considerable distance. The experiment of descending it has much to excite the fears of a person unaccustomed to river travels, but as yet it has been unmarked by accident.
Below this rapid we enter upon the last one hundred and eighty miles between us and the Missouri. The river, which to this point has displayed its beauties in long reaches of ten and twelve miles, now becomes crooked like the Missouri. Its banks are constantly crumbling, and its channel as constantly shifting. Everything in sight but adds to the desolation of the scenery, and the traveller finds it hard to realize that he is sailing on the same river which he beheld but yesterday so gloriously arrayed. The same general features are apparent to its mouth. It is much larger and wider than the Missouri at its junction with it, and increases to more than twice its size the latter, which, as all are aware, for more than a thousand miles below the Yellowstone has fewer attractions than any other river in the world.
Not so, however, the upper Missouri. That, like the Yellowstone, passes through a picturesque and beautiful country. From its source, where the Madison, Jefferson, and Gallatin unite to form it, to Fort Benton, a distance of two hundred miles, it exhibits a great variety of interesting and stupendous scenery, both of water, valley, rock, and mountain. There are the Great Falls, the Gate of the Mountains, and the passage of the river through numerous cañons, which, in any other portion of the country than the mountains and rocks of Montana, would be unparalleled for grandeur and sublimity.