It will be seen, by occasional remarks on the geological formation, that the constituents of the soil in these regions are good, and every day served to strengthen the impression in my mind, confirmed by subsequent observation, that the barren appearance of the country is due almost entirely to the extreme dryness of the climate. Along our route, the country had seemed to increase constantly in elevation. According to the indication of the barometer, we were at our encampment 5,440 feet above the sea. The evening was very clear, with a fresh breeze from the south, 50 deg. east. The barometer at sunset was 24.862, the thermometer attached showing 68 deg. I supposed this to be a fork of Lodge Pole creek, so far as I could determine from our uncertain means of information. Astronomical observations gave for the camp a longitude of 104 deg. 39' 37", and latitude 41 deg. 08' 31". 14th.--The wind continued fresh from the same quarter in the morning; the day being clear, with the exception of a few clouds in the horizon. At our camp, at six o'clock, the height of the barometer was 24.830, the attached thermometer 61 deg. Our course this morning was directly north by compass, the variation being 15 deg. or 16 deg. easterly. A ride of four miles brought us to Lodge Pole creek, which we had seen at the mouth of the South fork; crossing on the way two dry streams, in eighteen miles from our encampment of the past night, we reached a high bleak ridge, composed entirely of the same earthy limestone and marl previously described. I had never seen any thing which impressed so strongly on my mind a feeling of desolation. The valley, through which ran the waters of Horse creek, lay in view to the north, but too far to have any influence on the immediate view. On the peak of the ridge where I was standing, some seven hundred feet above the river, the wind was high and bleak; the barren and arid country seemed as if it had been swept by fires, and in every direction the same dull ash-colored hue, derived from the formation, met the eye. On the summits were some stunted pines, many of them dead, all wearing the same ashen hue of desolation. We left the place with pleasure; and, after we had descended several hundred feet, halted in one of the ravines, which, at the distance of every mile or two, cut the flanks of the ridge with little rushing streams, wearing something of a mountain character. We had already begun to exchange the comparatively barren lands for those of a more fertile character. Though the sandstone formed the broken banks of the creek, yet they were covered with a thin grass; and the fifty or sixty feet which formed the bottom land of the little stream were clothed with very luxuriant grass, among which I remarked willow and cherry, (_cerasus virginiana_,) and a quantity of gooseberry and currant bushes occupied the greater part.