Beyond the Muscle-shell river, which the voyagers reached on the 21st, the shores of the Missouri were abrupt and bold, and composed of a black and yellow clay.
After a navigation of two months, and a progress of more than a thousand miles from their winter camp, the party became considerably embarrassed, at the conflux of two rivers, which were, apparently, of equal magnitude. It was important for them to decide which of the streams in question was the true Missouri; because the river, which it was their object to ascend, was described to be at no great distance from the head waters, running, from the opposite side of the Rocky Mountains, towards the Pacific ocean. Two canoes, with three men, were consequently dispatched, to survey each of these doubtful streams; and parties were sent out by land, to discover, if possible, from the rising grounds, the distant bearings of the lofty ranges of mountains, which were conspicuous in the west; and some of which, though it was now the month of June, were covered with snow. Hence, there was no doubt of their vicinity to the great central ridge of American mountains; but the direction of the rivers just mentioned, could not be distinguished to any considerable distance. Of the two, the one coming from the north, had the brown colour and thick appearance of the Missouri; while the southern river had a rapid current, a pebbly bed, and transparent water, as if it issued from a mountainous country. The resemblance of the former to the river already navigated, led nearly all the privates of the party to consider it as the Missouri; but the clearness of the other stream induced the two captains to the conclusion that it proceeded from those central mountains, which were the grand objects of their search. After a further investigation, they resolved to pursue the course of the latter.
It was, however, requisite to make a deposit of all the heavy baggage, that could possibly be spared, as the increasing shallowness of the water would soon render the navigation much more laborious than it had hitherto been. They accordingly adopted a plan, common among traders who bring merchandise into the country of Indians of doubtful integrity, that of digging a hole in the ground, small at the top, but widened in the descent, somewhat like the shape of a kettle. Choice was made of a dry situation; and the sod, being carefully removed, the excavation was completed, a flooring of wood and hides was laid at the bottom, and the goods were covered with skins: the earth was then thrown into the river, and the sod laid on again with so much care, that not the slightest appearance remained of the surface having been disturbed.
These arrangements being completed, Captain Clarke took charge of the canoes; while Captain Lewis, with four men, proceeded by land, in hopes of soon putting it beyond a doubt that the river which they were now ascending was the Missouri. The decisive proof was to be sought in its falls, which the Indians had described as not remote from the Rocky Mountains, and as of remarkable grandeur. Captain Lewis passed along the direction of the river, during two days, and, on the next day, found himself in a position which overlooked a most beautiful plain.
Finding that the river here bore considerably to the south; and fearful of passing the falls before he reached the Rocky Mountains, he now changed, his course towards the south, and, leaving these hills to the right, proceeded across the plain. In this direction he had gone about two miles, when his ears were saluted with the agreeable sound of a fall of water; and, as he advanced, a spray, which seemed to be driven by the high south-west wind, arose above the plain, like a column of smoke, and vanished in an instant. Towards this point he directed his steps; and the noise, increasing as he approached, soon became too tremendous to be mistaken for any thing but the Great Falls of the Missouri. Having travelled seven miles after he first heard the sound, he at length reached the falls.
The hills became difficult of access, and were two hundred feet high. Down these he hurried with impatience; and, seating himself on some rocks under the centre of the falls, he enjoyed the sublime spectacle of this stupendous object; which, since the creation of the world, had been lavishing its magnificence on the desert, unknown to civilization. For ninety or a hundred yards from the left cliff, the water falls in one smooth, even sheet, over a precipice of at least eighty feet. The remaining part of the river precipitates itself with a more rapid current; but, being received, as it falls, by the irregular and somewhat projecting rocks below, it forms a splendid prospect of perfectly white foam, two hundred yards in length, and eighty yards in perpendicular elevation. This spray is dissipated into a thousand shapes, sometimes flying up in columns fifteen or twenty feet high; and then being oppressed by larger masses of white foam, which exhibit all the brilliant colours of the rainbow.
On the 14th of June, one of the men was sent to Captain Clarke, with an account of the discovery of the falls; and Captain Lewis proceeded to examine the rapids above. From the falls, he directed his course, south-west, up the river. After passing one continued rapid, and three small cascades, each three or four feet high, he reached, at the distance of five miles, a second fall. Above this, the river bends suddenly towards the north. Here captain Lewis heard a loud roar above him; and, crossing the point of a hill, for a few hundred yards, he saw one of the most beautiful objects in nature: the whole Missouri is suddenly stopped by one shelving rock, which, without a single niche, and with an edge as straight and regular as if formed by art, stretches from one side of the river to the other, for at least a quarter of a mile. Over this, the water precipitates itself, in an even, uninterrupted sheet, to the perpendicular depth of fifty feet; whence, dashing against the rocky bottom, it rushes rapidly down, leaving behind it a spray of the purest foam.
The scene here presented was indeed singularly beautiful; since, without any of the wild, irregular, sublimity of the lower falls, it combined all the regular elegancies which the fancy of a painter would select to form a beautiful cataract. Captain Lewis now ascended the hill which was behind him, and saw, from its top, a delightful plain, extending from the river to the base of the Snowy Mountains. Along this wide, level country, the Missouri pursued its winding course, filled with water, to its even and grassy banks; while, about four miles above, it was joined by a large river, flowing from the north-west, through a valley three miles in width, and distinguished by the timber which adorned its shores: the Missouri itself stretched to the south, in one unruffled stream of water; and bearing on its bosom, vast flocks of geese, while numerous herds of buffaloes were feeding on the plains which surround it.
Captain Lewis then descended the hills, and directed his course towards the river. Here he met a herd of at least a thousand buffaloes; and, being desirous of providing for his supper, he shot one of them. The animal immediately began to bleed; and the captain, having forgot to reload his rifle, was intently watching to see him fall, when he beheld a large brown bear, cautiously approaching him, and already within twenty yards. In the first moment of surprise, he lifted his rifle; but, recollecting that it was not charged, and that he had no time to reload, he felt that there was no safety but in flight. He was in an open, level plain; not a bush nor a tree was within three hundred yards of him; and the bank of the river was sloping, and not more than three feet high, so that there was no possible mode of concealment. Captain Lewis therefore thought of retreating, in a quick walk. He did so, but the bear approached, open mouth and at full speed, upon him. He ran about eighty yards; but finding that the animal gained on him fast, he plunged into the river, about waist deep, and, then facing about, presented the point of an espontoon or kind of spear, which he had carried in his hand. The bear arrived at the water's edge, within twenty feet of him; but, as soon as the captain put himself in this posture of defence, the animal seemed frightened, and, wheeling about, retreated with as much precipitation as he had pursued.
With respect to Captain Clarke, he and his canoes advanced up the river, but they proceeded very slowly; for the rapidity of the current, the number of large stones, and the numerous shoals and islands, greatly impeded their progress. After they had passed a stream, to which he gave the name of Maria's river, they redoubled their exertions. It, however, soon became necessary for them once more to lighten the canoes. They did so, and filled another hole, with a portion of their provisions and ammunition.