2d.--Temperature at sunrise 52°, and scenery and weather made our road to- day delightful. The neighboring mountain is thickly studded with pines, intermingled with the brighter foliage of aspens, and occasional spots like lawns between the patches of snow among the pines, and here and there on the heights. Our route below lay over a comparative plain, covered with the same brilliant vegetation, and the day was clear and pleasantly cool. During the morning, we crossed many streams, clear and rocky, and broad grassy valleys, of a strong black soil, washed down from the mountains, and producing excellent pasturage. These were timbered with the red willow and long-leaved cottonwood, mingled with aspen, as we approached the mountain more nearly towards noon. Esparcette was a characteristic, and flax occurred frequently in bloom. We halted at noon on the most western fork of Laramie river--a handsome stream about sixty feet wide and two feet deep, with clear water and a swift current, over a bed composed entirely of boulders or roll-stones. There was a large open bottom here, on which were many lodge poles lying about: and in the edge of the surrounding timber were three strong forts, that appeared to have been recently occupied. At this place I became first acquainted with the yampah, (anethum graveolens,) which I found our Snake woman engaged in digging in the low timbered bottom of the creek. Among the Indians along the Rocky Mountains, and more particularly among the Shoshonee or Snake Indians, in whose territory it is very abundant, this is considered the best among the roots used for food. To us it was an interesting plant--a little link between the savage and civilized life. Here, among the Indians, its root is a common article of food, which they take pleasure in offering to strangers; while with us, in a considerable portion of America and Europe, the seeds are used to flavor soup. It grows more abundantly, and in greater luxuriance, on one of the neighboring tributaries of the Colorado, than in any other part of this region; and on that stream, to which the Snakes are accustomed to resort every year to procure a supply of their favorite plant, they have bestowed the name of Yampah river. Among the trappers it is generally known as Little Snake river; but in this and other instances, where it illustrated the history of the people inhabiting the country, I have preferred to retain on the map the aboriginal name. By a meridional observation, the latitude is 41° 45' 59"

In the afternoon we took our way directly across the spurs from the point of the mountain, where we had several ridges to cross; and, although the road was not rendered bad by the nature of the ground, it was made extremely rough by the stiff tough bushes of artemisia tridentata, [Footnote: The greater portion of our subsequent journey was through a region where this shrub constituted the tree of the country; and, as it will often be mentioned in occasional descriptions, the word artemisia only will be used, without the specific name.] in this country commonly called sage.

This shrub now began to make its appearance in compact fields; and we were about to quit for a long time this country of excellent pasturage and brilliant flowers. Ten or twelve buffalo bulls were seen during the afternoon; and we were surprised by the appearance of a large red ox. We gathered around him as if he had been an old acquaintance, with all our domestic feelings as much awakened as if we had come in sight of an old farm-house. He had probably made his escape from some party of emigrants on Green river; and, with a vivid remembrance of some old green field, be was pursuing the straightest course for the frontier that the country admitted. We carried him along with us as a prize; and, when it was found in the morning that he had wandered off, I would not let him be pursued, for I would rather have gone through a starving time of three entire days, than let him be killed after he had successfully run the gauntlet so far among the Indians. I have been told by Mr. Bent's people of an ox born and raised at St. Vrain's fort, which made his escape from them at Elm grove, near the frontier, having come in that year with the wagons. They were on their way out, and saw occasionally places where he had eaten and laid down to rest; but did not see him for about 700 miles, when they overtook him on the road, traveling along to the fort, having unaccountably escaped Indians and every other mischance.

We encamped at evening on the principal fork of Medicine Bow river, near to an isolated mountain called the Medicine Butte, which appeared to be about 1,800 feet above the plain, from which it rises abruptly, and was still white, nearly to its base, with a great quantity of snow. The streams were timbered with the long-leaved, cottonwood and red willow; and during the afternoon a species of onion was very abundant. I obtained here an immersion of the first satellite of Jupiter, which, corresponding very nearly with the chronometer, placed us in longitude 106° 47' 25". The latitude, by observation, was 41° 37' 16"; elevation above the sea, 7,800 feet, and distance from St. Vrain's fort, 147 miles.

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.

A successful day's hunt had kept our hunters occupied until late, and they slept out, but rejoined us at daybreak, when, finding ourselves only about a mile from the river, we followed the ravine down, and camped in a cottonwood grove on a beautiful grassy bottom, where our animals indemnified themselves for the scanty fare of the past night. It was quite a pretty and pleasant place; a narrow strip of prairie, about five hundred yards long, terminated at the ravine where we entered by high precipitous hills closing in upon the river, and at the upper end by a ridge of low rolling hills.

In the precipitous bluffs were displayed a succession of strata containing fossil vegetable remains, and several beds of coal. In some of the beds the coal did not appear to be perfectly mineralized, and in some of the seams it was compact, and remarkably lustrous. In these latter places, there were also thin layers of a very fine white salts, in powder. As we had a large supply of meat in the camp, which it was necessary to dry, and the surrounding country appeared to be well stocked with buffalo, which it was probable, after a day or two, we would not see again until our return to the Mississippi waters, I determined to make here a provision of dried meat, which would be necessary for our subsistence in the region we were about entering, which was said to be nearly destitute of game. Scaffolds were accordingly soon erected, fires made, and the meat cut into thin slices to be dried; and all were busily occupied, when the camp was thrown into a sudden tumult, by a charge from about seventy mounted Indians, over the low hills at the upper end of the little bottom. Fortunately, the guard, who was between them and our animals, had caught a glimpse of an Indian's head, as he raised himself in his stirrups to look over the hill, a moment before he made the charge, and succeeded in turning the band into the camp, as the Indians charged into the bottom with the usual yell. Before they reached us, the grove on the verge of the little bottom was occupied by our people, and the Indians brought to a sudden halt, which they made in time to save themselves from a howitzer shot, which would undoubtedly have been very effective in such a compact body; and further proceedings were interrupted by their signs for peace. They proved to be a war party of Arapaho and Cheyenne Indians, and informed us that they had charged upon the camp under the belief that we were hostile Indians, and had discovered their mistake only at the moment of the attack--an excuse which policy required us to receive as true, though under the full conviction that the display of our little howitzer, and our favorable position in the grove, certainly saved our horses, and probably ourselves, from their marauding intentions. They had been on a war party, and had been defeated, and were consequently in the state of mind which aggravates their innate thirst for plunder and blood. Their excuse, however, was taken in good part, and the usual evidences of friendship interchanged. The pipe went round, provisions were spread, and the tobacco and goods furnished the customary presents, which they look for even from traders, and much more from government authorities.

They were returning from an expedition against the Shoshonee Indians, one of whose villages they had surprised, at Bridger's fort, on Ham's fork of Green river, (in the absence of the men, who were engaged in an antelope surround,) and succeeded in carrying off their horses, and taking several scalps. News of the attack reached the Snakes immediately, who pursued and overtook them, and recovered their horses; and, in the running fight which ensued, the Arapahoes had lost several men killed, and a number wounded, who were coming on more slowly with a party in the rear. Nearly all the horses they had brought off were the property of the whites at the fort. After remaining until nearly sunset, they took their departure; and the excitement which their arrival had afforded subsided into our usual quiet, a little enlivened by the vigilance rendered necessary by the neighborhood of our uncertain visiters. At noon the thermometer was at 75°, at sunset 70°, and the evening clear. Elevation above the sea 6,820 feet; latitude 41° 36' 00"; longitude 107° 22' 27".

6th.--At sunrise the thermometer was 46°, the morning being clear and calm. We traveled to-day over an extremely rugged country, barren and uninteresting--nothing to be seen but artemisia bushes; and, in the evening, found a grassy spot among the hills, kept green by several springs, where we encamped late. Within a few hundred yards was a very pretty little stream of clear cool water, whose green banks looked refreshing among the dry, rocky hills. The hunters brought in a fat mountain sheep, (ovis montana.)