about a bold and lofty point, called the Sheep Rock, running away to the South West. Here, also, it seems to have made a breach through the Mountain, into another valley. Formerly, the Blackfeet Indians frequented this country; and, at this Rock, they had repeated battles with the Mountaineers, and with other tribes of Indians: and here the effects of their deadly encounters may still be seen, in bleached skulls and scattered bones. At this point, we left the river, and bore off to the right, across the valley, which is about ten miles wide. This valley appears to have been sunk several feet, and is full of chasms, from two to twenty feet wide, and of unknown depths. Volcanic rock is scattered over it, in large masses; and in many places, it appears to have been upheaved from beneath. We passed, on the left, a large, hollow mound, the crater of an extinguished Volcano.
It was late in the night before we reached the Western side of the valley, and found wood and water for our camp. The water upon which we encamped, was a branch of the Portneiff, a tributary of Snake or Lewis river. We noticed, scattered over the country, a kind of black volcanic glass, shaped like the fragments of a broken bottle. Winding our way through the hills, by a very circuitous route, on the 13th of September we arrived at Fort Hall. It is situated on the South bank of Snake River, in a rich valley, about twelve miles wide and twenty-five miles long, and in latitude about 43 deg. 20 min. North. The Portneiff, Black Foot, and many other small streams, run through this valley of Fort Hall. The streams are lined with a fine growth of Cotton Wood timber, and the entire valley abounds in excellent grass. The company keep several hundred cattle and horses, at this place, which live through the winter, generally, without much attention. We were told by one of the members of the Company, that wheat had been sown at the Fort, and grew well. Fort Hall is built of the same material, and nearly in the same manner, as the Forts on the Platte are.
Leaving Fort Hall, we traveled down the South bank of Snake River, and a few miles below, we crossed the Portneiff, a beautiful little stream emptying into it; and at eighteen miles, came to the Americn Falls. Here, the River, compressed into about two thirds of its usual width, runs down, over rugged volcanic rock, a descent of about twenty-five feet in one hundred. The water is divided into three different shoots, by two large rocks on the Falls. In the middle shoot, there is scarcely any perpendicular
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