"10th.--We continued along the same fine plainly beaten road, which the smooth surface of the country afforded us, for a distance of six hundred and thirty miles, from the frontiers of Missouri to the Laramie fork. In the course of the day we met some whites, who were following along in the train of Mr. Bridger; and, after a day's journey of twenty-four miles, encamped about sunset at the Chimney rock. It consists of marl and earthy limestone, and the weather is rapidly diminishing its height, which is not more than two hundred feet above the river. Travelers who visited it some years since, placed its height at upwards of 500 feet. "11th.--The valley of the North fork is of a variable breadth, from one to four, and sometimes six miles. Fifteen miles from the Chimney rock we reached one of those places where the river strikes the bluffs, and forces the road to make a considerable circuit over the uplands. This presented an escarpment on the river of about nine hundred yards in length, and is familiarly known as Scott's bluffs. We had made a journey of thirty miles before we again struck the river, at a place where some scanty grass afforded an insufficient pasturage to our animals. About twenty miles from the Chimney rock we had found a very beautiful spring of excellent and cold water; but it was in such a deep ravine, and so small, that the animals could not profit by it, and we therefore halted only a few minutes, and found a resting-place ten miles further on. The plain between Scott's bluffs and Chimney rock was almost entirely covered with drift-wood, consisting principally of cedar, which, we were informed, had been supplied from the Black hills, in a flood five or six years since. "12th.--Nine miles from our encampment of yesterday we crossed Horse creek, a shallow stream of clear water, about seventy yards wide, falling into the Platte on the right bank. It was lightly timbered, and great quantities of drift-wood were piled up on the banks, appearing to be supplied by the creek from above. After a journey of twenty-six miles, we encamped on a rich bottom, which afforded fine grass to our animals. Buffalo have entirely disappeared, and we live now upon the dried meat, which is exceedingly poor food. The marl and earthy limestone, which constituted the formation for several days past, had changed, during the day, into a compact white or grayish-white limestone, sometimes containing hornstone; and at the place of our encampment this evening, some strata in the river hills cropped out to the height of thirty or forty feet, consisting of fine-grained granitic sandstone; one of the strata closely resembling gneiss.