Thursday, 25, at the distance of a few miles he arrived at the three forks of the Missouri. Here he found that the plains had been recently burnt on the north side, and saw the track of a horse which seemed to have passed about four or five days since. After breakfast he examined the rivers, and finding that the north branch, although not larger, contained more water than the middle branch, and bore more to the westward, he determined to ascend it. He therefore left a note informing captain Lewis of his intention, and then went up that stream on the north side for about twenty-five miles. Here Chaboneau was unable to proceed any further, and the party therefore encamped, all of them much fatigued, their feet blistered and wounded by the prickly pear.
In the meantime we left our camp, and proceeded on very well, though the water is still rapid and has some occasional ripples. The country is much like that of yesterday: there are however fewer islands, for we passed only two. Behind one of them is a large creek twenty-five yards wide, to which we gave the name of Gass's creek, from one of our serjeants, Patrick Gass: it is formed by the union of five streams, which descend from the mountains and join in the plain near the river. On this island we saw a large brown bear, but he retreated to the shore and ran off before we could approach him. These animals seem more shy than they were below the mountains. The antelopes have again collected in small herds, composed of several females with their young, attended by one or two males, though some of the males are still solitary or wander in parties of two over the plains, which the antelope invariably prefers to the woodlands, and to which it always retreats if by accident it is found straggling in the hills, confiding no doubt in its wonderful fleetness. We also killed a few young geese, but as this game is small and very incompetent to the subsistence of the party, we have forbidden the men any longer to waste their ammunition on them. About four and a half miles above Gass's creek, the valley in which we have been travelling ceases, the high craggy cliffs again approach the river, which now enters or rather leaves what appears to be a second great chain of the Rocky mountains. About a mile after entering these hills or low mountains we passed a number of fine bold springs, which burst out near the edge of the river under the cliffs on the left, and furnished a fine freestone water: near these we met with two of the worst rapids we have seen since entering the mountains; a ridge of sharp pointed rocks stretching across the river, leaving but small and dangerous channels for the navigation. The cliffs are of a lighter colour than those we have already passed, and in the bed of the river is some limestone which is small and worn smooth, and seems to have been brought down by the current. We went about a mile further and encamped under a high bluff on the right opposite to a cliff of rocks, having made sixteen miles.
All these cliffs appeared to have been undermined by the water at some period, and fallen down from the hills on their sides, the stratas of rock sometimes lying with their edges upwards, others not detached from the hills are depressed obliquely on the side next the river as if they had sunk to fill up the cavity formed by the washing of the river.
In the open places among the rocky cliffs are two kinds of gooseberry, one yellow and the other red. The former species was observed for the first time near the falls, the latter differs from it in no respect except in colour and in being of a larger size; both have a sweet flavour, and are rather indifferent fruit.
Friday 26. We again found the current strong and the ripples frequent: these we were obliged to overcome by means of the cord and the pole, the oar being scarcely ever used except in crossing to take advantage of the shore. Within three and three quarter miles we passed seven small islands and reached the mouth of a large creek which empties itself in the centre of a bend on the left side: it is a bold running stream fifteen yards wide, and received the name of Howard creek after John P. Howard one of the party. One mile beyond it is a small run which falls in on the same side just above a rocky cliff. Here the mountains recede from the river, and the valley widens to the extent of several miles. The river now becomes crowded with islands of which we passed ten in the next thirteen and three quarter miles, then at the distance of eighteen miles we encamped on the left shore near a rock in the centre of a bend towards the left, and opposite to two more islands. This valley has wide low grounds covered with high grass, and in many with a fine turf of green sward. The soil of the highlands is thin and meagre, without any covering except a low sedge and a dry kind of grass which is almost as inconvenient as the prickly pear. The seeds of it are armed with a long twisted hard beard at their upper extremity, while the lower part is a sharp firm point, beset at its base with little stiff bristles, with the points in a direction contrary to the subulate point to which they answer as a barb. We see also another species of prickly pear. It is of a globular form, composed of an assemblage of little conic leaves springing from a common root to which their small points are attached as a common centre, and the base of the cone forms the apex of the leaf which is garnished with a circular range of sharp thorns like the cochineal plant, and quite as stiff and even more keen than those of the common flat-leafed species. Between the hills the river had been confined within one hundred and fifty or two hundred yards, but in the valley it widens to two hundred or two hundred and fifty yards, and sometimes is spread by its numerous islands to the distance of three quarters of a mile. The banks are low, but the river never overflows them. On entering the valley we again saw the snow-clad mountains before us, but the appearance of the hills as well as of the timber near us is much as heretofore.
Finding Chaboneau unable to proceed captain Clarke left him with one of the men, and accompanied by the other went up the river about twelve miles to the top of a mountain. Here he had an extensive view of the river valley upwards and saw a large creek which flowed in on the right side. He however discovered no fresh sign of the Indians, and therefore determined to examine the middle branch and join us by the time we reached the forks: he descended the mountain by an Indian path which wound through a deep valley, and at length reached a fine cold spring. The day had been very warm, the path unshaded by timber, and his thirst was excessive; he was therefore tempted to drink: but although he took the precaution of previously wetting his head, feet and hands, he soon found himself very unwell; he continued his route, and after resting with Chaboneau at his camp, resumed his march across the north fork near a large island. The first part was knee deep, but on the other side of the island the water came to their waists and was so rapid that Chaboneau was on the point of being swept away, and not being able to swim would have perished if captain Clarke had not rescued him. While crossing the island they killed two brown bear and saw great quantities of beaver. He then went on to a small river which falls into the north fork some miles above its junction with the two others: here, finding himself grow more unwell, he halted for the night at the distance of four miles from his last encampment.
Saturday 27. We proceeded on but slowly, the current being still so rapid as to require the utmost exertions of us all to advance, and the men are losing their strength fast in consequence of their constant efforts. At half a mile we passed an island, and a mile and a quarter further again entered a ridge of hills which now approach the river with cliffs apparently sinking like those of yesterday. They are composed of a solid limestone of a light lead colour when exposed to the air, though when freshly broken it is of a deep blue, and of an excellent quality and very fine grain. On these cliffs were numbers of the bighorn. At two and a half miles we reached the centre of a bend towards the south passing a small island, and at one mile and a quarter beyond this reached about nine in the morning the mouth of a river seventy yards wide, which falls in from the southeast. Here the country suddenly opens into extensive and beautiful meadows and plains, surrounded on every side with distant and lofty mountains. Captain Lewis went up this stream for about half a mile, and from the height of a limestone cliff could observe its course about seven miles, and the three forks of the Missouri, of which this river is one. Its extreme point bore S. 65° E. and during the seven miles it passes through a green extensive meadow of fine grass dividing itself into several streams, the largest passing near the ridge of hills on which he stood. On the right side of the Missouri a high, wide and extensive plain succeeds to this low meadow which reaches the hills. In the meadow a large spring rises about a quarter of a mile from this Southeast fork, into which it discharges itself on the right side about four hundred paces from where he stood. Between the southeast and middle forks a distant range of snow-topped mountains spread from east to south above the irregular broken hills nearer to this spot: the middle and southwest forks unite at half a mile above the entrance of the southeast fork. The extreme point at which the former can be seen, bears S. 15° E. and at the distance of fourteen miles, where it turns to the right round the point of a high plain and disappears from the view. Its low grounds are several miles in width, forming a smooth and beautiful green meadow, and like the southeast fork it divides itself into several streams. Between these two forks and near their junction with that from the southwest, is a position admirably well calculated for a fort. It is a limestone rock of an oblong form, rising from the plain perpendicularly to the height of twenty-five feet on three of its sides; the fourth towards the middle fork being a gradual ascent and covered with a fine green sward, as is also the top which is level and contains about two acres. An extensive plain lies between the middle and southwest forks, the last of which after watering a country like that of the other two branches, disappears about twelve miles off, at a point bearing south 30° west. It is also more divided and serpentine in its course than the other two, and possesses more timber in its meadows. This timber consists almost exclusively of the narrow-leafed cottonwood, with an inter-mixture of box alder and sweet-willow, the underbrush being thick and like that of the Missouri lower down. A range of high mountains partially covered with snow is seen at a considerable distance running from south to west, and nearly all around us are broken ridges of country like that below, through which those united streams appear to have forced their passage: after observing the country captain Lewis descended to breakfast. We then left the mouth of the southeast fork, to which in honour of the secretary of the treasury we called Gallatin's river, and at the distance of half a mile reached the confluence of the southwest and middle branch of the Missouri. Here we found the letter from captain Clarke, and as we agreed with him that the direction of the southwest fork gave it a decided preference over the others, we ascended that branch of the river for a mile, and encamped in a level handsome plain on the left: having advanced only seven miles. Here we resolved to wait the return of captain Clarke, and in the meantime make the necessary celestial observations, as this seems an essential point in the geography of the western world, and also to recruit the men and air the baggage. It was accordingly all unloaded and stowed away on shore. Near the three forks we saw many collections of the mud-nests of the small martin attached to the smooth faces of the limestone rock, where they were sheltered by projections of the rock above it: and in the meadows were numbers of the duck or mallard with their young, who are now nearly grown. The hunters returned towards evening with six deer, three otter and a muskrat; and had seen great numbers of antelopes, and much sign of the beaver and elk.
During all last night captain Clarke had a high fever and chills accompanied with great pain. He however pursued his route eight miles to the middle branch, where not finding any fresh Indian track he came down it and joined us about three o'clock, very much exhausted with fatigue and the violence of his fever. Believing himself bilious he took a dose of Rush's pills, which we have always found sovereign in such cases, and bathing the lower extremities in warm water.
We are now very anxious to see the Snake Indians. After advancing for several hundred miles into this wild and mountainous country, we may soon expect that the game will abandon us. With no information of the route we may be unable to find a passage across the mountains when we reach the head of the river, at least such a one as will lead us to the Columbia, and even were we so fortunate as to find a branch of that river, the timber which we have hitherto seen in these mountains does not promise us any fit to make canoes, so that our chief dependence is on meeting some tribe from whom we may procure horses. Our consolation is, that this southwest branch can scarcely head with any other river than the Columbia, and that if any nation of Indians can live in the mountains we are able to endure as much as they, and have even better means of procuring subsistence.