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.