Thursday 18. This morning early before our departure we saw a large herd of the big-horned animals, who were bounding among the rocks in the opposite cliff with great agility. These inaccessible spots secure them from all their enemies, and the only danger is in wandering among these precipices, where we should suppose it scarcely possible for any animal to stand; a single false step would precipitate them at least five hundred feet into the water. At one mile and a quarter we passed another single cliff on the left; at the same distance beyond which is the mouth of a large river emptying itself from the north. It is a handsome, bold, and clear stream, eighty yards wide, that is nearly as broad as the Missouri, with a rapid current over a bed of small smooth stones of various figures. The water is extremely transparent, the low grounds are narrow, but possess as much wood as those of the Missouri; and it has every appearance of being navigable, though to what distance we cannot ascertain, as the country which it waters, is broken and mountainous. In honour of the secretary at war we called it Dearborn’s river. Being now very anxious to meet with the Shoshonees or Snake Indians, for the purpose of obtaining the necessary information of our route, as well as to procure horses, it was thought best for one of us to go forward with a small party and endeavour to discover them, before the daily discharge of our guns, which is necessary for our subsistence, should give them notice of our approach: if by an accident they hear us, they will most probably retreat to the mountains, mistaking us for their enemies who usually attack them on this side. Accordingly captain Clarke set out with three men, and followed the course of the river on the north side; but the hills were so steep at first that he was not able to go much faster than ourselves. In the evening however he cut off many miles of the circuitous course of the river, by crossing a mountain over which he found a wide Indian road which in many places seems to have been cut or dug down in the earth. He passed also two branches of a stream which he called Ordway’s creek, where he saw a number of beaver-dams extending in close succession towards the mountains as far as he could distinguish: on the cliffs were many of the big-horned animals. After crossing this mountain he encamped near a small stream of running water, having travelled twenty miles.
On leaving Dearborn’s river we passed at three and a half miles a small creek, and at six beyond it an island on the north side of the river, which makes within that distance many small bends. At two and a half miles further is another island: three quarters of a mile beyond this is a small creek on the north side. At a mile and a half above the creek is a much larger stream thirty yards wide, and discharging itself with a bold current on the north side: the banks are low, and the bed formed of stones altogether. To this stream we gave