After the junction of the three branches before mentioned, the river continues a considerable distance to be still a foaming mountain torrent. It then spreads into a broad and comparatively gentle stream full of islands. Precipitous peaks of blackish rock frown above the river in perpendicular elevations of a thousand feet. The mountains whose bases it sweeps are covered with pines, cedars and firs; and mountain sheep are seen bounding on their summits where they are apparently inaccessible. In this distance the mountains have an aspect of inexpressible loneliness and grandeur. In the meadows and along the shore the tree most common is the cotton-wood, which with the willow forms almost the exclusive growth of the Missouri.
About forty-seven miles below the spot where the Missouri issues from the mountains to the plains, a most sublime and extraordinary spectacle presents itself, emphatically denominated the Gates of the Rocky Mountains. In ascending the stream it increases in rapidity, depth, and breadth, to the mouth of this formidable pass. Here the rocks approach it on both sides, rising perpendicularly from the edge of the water to the height of one thousand two hundred feet. Near the base they are composed of black granite; but above, the color is of a yellowish, brown, and cream color. Nothing can be imagined more tremendous than the frowning darkness of these rocks, which project over the river, and menace the passenger with instant destruction. For the space of five miles and three quarters, the rocks rise to the above degree of elevation, and the river, three hundred and fifty yards broad, seems to have forced its channel down the solid mass; or, to use Volney’s expression respecting the falls of Niagara, literally to have sawed a passage through this body of hard and solid rock, near six miles in length, being incased as it were, during all this distance, between two walls of one thousand and two hundred feet high. During the whole distance the water is very deep, even at the edges; and for the first three miles, there is not a spot, except one of a few yards, in which a man could stand between the water and the towering perpendicular precipice of the mountain.
The river, for the distance of about seventeen miles, becomes almost a continued cataract. In this distance its perpendicular descent is three hundred and sixty-two feet. The first fall is ninety-eight feet; the second, nineteen; the third, forty-seven; the fourth, twenty-six. Next to the Niagara these falls are the grandest in the world. The river continues rapid for a long distance beyond, but there is not much variation in its appearance till near the mouth of the Platte. That powerful river throws out vast quantities of coarse sand, which contribute to give a new face to the Missouri, which is now much more impeded by islands. The sand, as it is drifted down, adheres in time to some of the projecting points from the shore, and forms a barrier to the mud which at length fills to the same height with the sand-bar itself. As soon as it has acquired a consistency, the willow grows there the first year, and by its roots gives solidity to the whole; with further accumulations the cotton-wood tree next appears, till the soil is gradually raised to a point above the highest freshets. Thus stopped in its course, the water seeks a passage elsewhere, and as the soil on each side is light and yielding, what was only a peninsula becomes gradually an island, and the river compensates the usurpation by encroaching on the adjacent shore. In this way the Missouri, like the Mississippi, is continually cutting off the projections of the shore, and leaving its ancient channel, which may be traced by the deposits of mud and a few stagnant ponds.6
During the whole length of the Missouri below the Platte, the soil is generally excellent, and although the timber is scarce, there is still sufficient for the purpose of settlers. But beyond that river, although the soil is still rich, yet the almost total absence of timber, and particularly the want of good water, of which there is but a small quantity in the creeks, oppose very powerful impediments to its occupancy. The prairies for many miles on each side of the river produce abundance of good pasturage.
Above the mouth of the Osage, the immediate valley of the Missouri gradually expands, embracing some wide bottoms in which are many settlements gradually increasing in the number of inhabitants. The Manito Rocks, and some other precipitous cliffs, are the terminations of low ranges of hills, running in quite to the river. These hills sometimes occasion rapids, and opposite the Manito rocks a small group of islands stretches obliquely across the river, separated by narrow channels in which the current is stronger than below. This group is called the Thousand Islands. Some of the channels are obstructed by collections of floating trees, which usually accumulate about the heads of islands, and are here called rafts. After increasing to a certain extent, portions of these rafts become loosened, and float down the river, covering nearly its whole surface, and greatly impeding and endangering the progress of the ascending boats.
Council Bluffs, the seat of an important military establishment of the United States, about six hundred miles up the Missouri, is a remarkable bank, rising abruptly from the brink of the river to an elevation of one hundred and fifty feet. From the hill tops, a mile in the rear of the Bluffs, is presented a most extensive and beautiful landscape. On the east side of the river, the Bluffs exhibit a chain of peaks, stretching as far as the eye can reach. The river is here and there seen meandering in serpentine folds along its broad valley, chequered with woodlands and prairies, while, at a nearer view, you look down on an extensive plain, interspersed with a few scattered copses or bushes, and terminated at a distance by the Council Bluffs.
Taken in connection with the Mississippi into which it flows, this river is the longest on the globe.7 Its whole course, from its mouth in the gulf of Mexico to its source in the Rocky Mountains, is four thousand four hundred and twenty-four miles, including its windings; and for four thousand three hundred and ninety-six miles of this course it is navigable. From the point of its confluence with the Mississippi to fort Mandan, it is one thousand six hundred and nine miles; to the foot of the rapids at Great Falls two thousand five hundred and seventy-five miles; two thousand six hundred and sixty-four to where it issues from the mountains; two thousand six hundred and ninety to the Gates of the Mountains; three thousand and ninety-six to the extreme navigable point of Jefferson river; and three thousand one hundred and twenty-four miles to its remotest source. In this immense course it receives upwards of fifty large rivers, and one hundred and fifty smaller streams. Its principal tributaries are the Roche Jaune, or Yellowstone, the Kansas, Platte, Osage, Gasconade, Little Missouri, Running Water, Charaton, White, and Milk rivers.
The Yellowstone is the largest of these tributaries. Its sources are in the Rocky Mountains, near those of the Missouri and the Platte, and it may be navigated in canoes almost to its head. It runs first through a mountainous country, but in many parts fertile and well timbered; it then waters a rich, delightful land, broken into valleys and meadows, and well supplied with wood and water, till it reaches near the Missouri open meadows and low grounds, sufficiently timbered on its borders. In the upper country its course is said to be very rapid, but during the two last and largest portions, its current is much more gentle than that of the Missouri. On the