3d.--There was a white frost last night; the morning is clear and cool. We were early on the road, having breakfasted before sunrise, and in a few miles' travel entered the pass of the Medicine _Butte_, through which led a broad trail, which had been recently traveled by a very large party. Immediately in the pass, the road was broken by ravines, and we were obliged to clear a way through groves of aspens, which generally made their appearance when we reached elevated regions. According to the barometer, this was 8,300 feet; and while we were detained in opening a road, I obtained a meridional observation of the sun, which gave 41° 35' 48" for the latitude of the pass. The Medicine _Butte_ is isolated by a small tributary of the North fork of the Platte, but the mountains approach each other very nearly; the stream running at their feet. On the south they are smooth, with occasional streaks of pine; but the butte itself is ragged, with escarpments of red feldspathic granite, and dark with pines; the snow reaching from the summit to within a few hundred feet of the trail. The granite here was more compact and durable than that in the formation which we had passed through a few days before to the eastward of Laramie. Continuing our way over a plain on the west side of the pass, where the road was terribly rough with artemisia, we made our evening encampment on the creek, where it took a northern direction, unfavorably to the course we were pursuing. Bands of buffalo were discovered as we came down upon the plain; and Carson brought into the camp a cow which had the fat on the fleece two inches thick. Even in this country of rich pasturage and abundant game, it is rare that a hunter chances upon a finer animal. Our voyage had already been long, but this was the first good buffalo meat we had obtained. We traveled to-day 26 miles.
4th.--The morning was clear and calm; and, leaving the creek, we traveled towards the North fork of the Platte, over a plain which was rendered rough and broken by ravines. With the exception of some thin grasses, the sandy soil here was occupied almost exclusively by artemisia, with its usual turpentine odor. We had expected to meet with some difficulty in crossing the river, but happened to strike it where there was a very excellent ford, and halted to noon on the left bank, two hundred miles from St. Vrain's fort. The hunters brought in pack-animals loaded with fine meat. According to our imperfect knowledge of the country, there should have been a small affluent to this stream a few miles higher up; and in the afternoon we continued our way among the river hills, in the expectation of encamping upon it in the evening. The ground proved to be so exceedingly difficult, broken up into hills, terminating in escarpments and broad ravines, five hundred or six hundred feet deep, with sides so precipitous that we could scarcely find a place to descend, that, towards sunset, I turned directly in towards the river, and, after nightfall, entered a sort of ravine. We were obliged to feel our way, and clear a road in the darkness; the surface being much broken, and the progress of the carriages being greatly obstructed by the artemisia, which had a luxuriant growth of four to six feet in height. We had scrambled along this gulley for several hours, during which we had knocked off the carriage-lamps, broken a thermometer and several small articles, when, fearing to lose something of more importance, I halted for the night at ten o'clock. Our animals were turned down towards the river, that they might pick up what little grass they could find; and after a little search, some water was found in a small ravine, and improved by digging. We lighted up the ravine with fires of artemisia, and about midnight sat down to a supper which we were hungry enough to find delightful--although the buffalo-meat was crusted with sand, and the coffee was bitter with the wormwood taste of the artemisia leaves.
