AUGUST.
1st.--The hunters went ahead this morning, as buffalo appeared tolerably abundant, and I was desirous to secure a small stock of provisions; and we moved about seven mules up the valley, and encamped one mile below Rock Independence. This is an isolated granite rock, about six hundred and fifty yards long, and forty in height. Except in a depression of the summit, where a little soil supports a scanty growth of shrubs, with a solitary dwarf pine, it is entirely bare. Everywhere within six or eight feet of the ground, where the surface is sufficiently smooth, and in some places sixty or eighty feet above, the rock is inscribed with the names of travelers. Many a name famous in the history of this country, and some well known to science, are to be found mixed among those of the traders and travelers for pleasure and curiosity, and of missionaries among the savages. Some of these have been washed away by the rain, but the greater number are still very legible. The position of this rock is in longitude 107° 56', latitude 42° 29' 36". We remained at our camp of August 1st until noon of the next day, occupied in drying meat. By observation, the longitude of the place is 107° 25' 23", latitude 42° 29' 56".
2d.--Five miles above Rock Independence we came to a place called the Devil's Gate, where the Sweet Water cuts through the point of a granite ridge. The length of the passage is about three hundred yards, and the width thirty-five yards. The walls of rock are vertical, and about four hundred feet in height; and the stream in the gate is almost entirely choked up by masses which have fallen from above. In the wall, on the right bank, is a dike of trap-rock, cutting through a fine-grained gray granite. Near the point of this ridge crop out some strata of the valley formation, consisting of a grayish micaceous sandstone, and fine-grained conglomerate, and marl. We encamped eight miles above the Devil's Gate. There was no timber of any kind on the river, but good fires were made of drift wood, aided by the bois de vache.
We had to-night no shelter from the rain, which commenced with squalls of wind about sunset. The country here is exceedingly picturesque. On either side of the valley, which is five miles broad, the mountains rise to the height of twelve and fifteen hundred or two thousand feet. On the south side, the range appears to be timbered, and to-night is luminous with fires--probably the work of the Indians, who have just passed through the valley. On the north, broken and granite masses rise abruptly from the green sward of the river, terminating in a line of broken summits. Except in the crevices of the rock, and here and there on a ledge or bench of the mountain, where a few hardy pines have clustered together, these are perfectly bare and destitute of vegetation.
Among these masses, where there are sometimes isolated hills and ridges, green valleys open in upon the river, which sweeps the base of these mountains for thirty-six miles. Everywhere its deep verdure and profusion of beautiful flowers is in pleasing contrast with the sterile grandeur of the rock and the barrenness of the sandy plain, which, from the right bank of the river, sweeps up to the mountain range that forms its southern boundary. The great evaporation on the sandy soil of this elevated plain, and the saline efflorescences which whiten the ground, and shine like lakes reflecting in the sun, make a soil wholly unfit for cultivation.
3d.--We were early on the road the next morning, traveling along the upper part of the valley, which is overgrown with artemisia. Scattered about on the plain are occasional small isolated hills. One of these which I have examined, about fifty feet high, consisted of white clay and marl, in nearly horizontal strata. Several bands of buffalo made their appearance to-day, with herds of antelope; and a grizzly bear --the only one we encountered during the journey--was seen scrambling up among the rocks. As we passed over a slight rise near the river, we caught the first view of the Wind River mountains, appearing, at this distance of about seventy miles, to be a low and dark mountainous ridge. The view dissipated in a moment the pictures which had been created in our minds, by many descriptions of travelers, who have compared these mountains to the Alps in Switzerland, and speak of the glittering peaks which rise in icy majesty amidst the eternal glaciers nine or ten thousand feet into the region of eternal snows. The nakedness of the river was relieved by groves of willows, where we encamped at night, after a march of twenty-six miles; and numerous bright-colored flowers had made the river bottom look gay as a garden. We found here a horse, which had been abandoned by the Indians, because his hoofs had been so much worn that he was unable to travel; and during the night a dog came into the camp.
4th.--Our camp was at the foot of the granite mountains, which we climbed this morning to take some barometrical heights; and here among the rocks was seen the first magpie. On our return, we saw one at the mouth of the Platte river. We left here one of our horses, which was unable to proceed farther. A few miles from the encampment we left the river, which makes a bend to the south, and traversing an undulating country, consisting of a grayish micaceous sandstone and fine-grained conglomerates, struck it again, and encamped after a journey of twenty-five miles. Astronomical observations placed us in latitude 42° 32' 30", and longitude 108° 30' 13".
5th.--The morning was dark, with a driving rain, and disagreeably cold. We continued our route as usual and the weather became so bad, that we were glad to avail ourselves of the shelter offered by a small island, about ten miles above our last encampment, which was covered with a dense growth of willows. There was fine grass for our animals, and the timber afforded us comfortable protection and good fires. In the afternoon, the sun broke through the clouds for a short time, and the barometer at 5 P.M. was 23.713, the thermometer 60°, with the wind strong from the northwest. We availed ourselves of the fine weather to make excursions in the neighborhood. The river, at this place, is bordered by hills of the valley formation. They are of moderate height; one of the highest peaks on the right bank being, according to the barometer, one hundred and eighty feet above the river. On the left bank they are higher. They consist of a fine white clayey sandstone, a white calcareous sandstone, and coarse sandstone or pudding-stone.
6th.--It continued steadily raining all day; but, notwithstanding, we left our encampment in the afternoon. Our animals had been much refreshed by their repose, and an abundance of rich, soft grass, which had been much improved by the rains. In about three miles, we reached the entrance of a kanyon, where the Sweet Water issues upon the more open valley we had passed over. Immediately at the entrance, and superimposed directly upon the granite, are strata of compact calcareous sandstone and chert, alternating with fine white and reddish-white, and fine gray and red sandstones. These strata dip to the eastward at an angle of about 18°, and form the western limit of the sandstone and limestone formations on the line of our route. Here we entered among the primitive rocks. The usual road passes to the right of this place; but we wound, or rather scrambled, our way up the narrow valley for several hours. Wildness and disorder were the character of this scenery. The river had been swollen by the late rains, and came rushing through with an impetuous current, three or four feet deep, and generally twenty yards broad. The valley was sometimes the breadth of the stream, and sometimes opened into little green meadows, sixty yards wide, with open groves of aspen. The stream was bordered throughout with aspen, beech, and willow; and tall pines grow on the sides and summits of the crags. On both sides the granite rocks rose precipitously to the height of three hundred and five hundred feet, terminating in jagged and broken pointed peaks; and fragments of fallen rock lay piled up at the foot of the precipices. Gneiss, mica slate, and a white granite, were among the varieties I noticed. Here were many old traces of beaver on the stream; remnants of dams, near which were lying trees, which they had cut down, one and two feet in diameter. The hills entirely shut up the river at the end of about five miles, and we turned up a ravine that led to a high prairie, which seemed to be the general level of the country. Hence, to the summit of the ridge, there is a regular and very gradual rise. Blocks of granite were piled up at the heads of the ravines, and small bare knolls of mica slate and milky quartz protruded at frequent intervals on the prairie, which was whitened in occasional spots with small salt lakes, where the water had evaporated, and left the bed covered with a shining incrustation of salt. The evening was very cold, a northwest wind driving a fine rain in our faces; and at nightfall we descended to a little stream, on which we encamped, about two miles from the Sweet Water. Here had recently been a very large camp of the Snake and Crow Indians; and some large poles lying about afforded the means of pitching a tent, and making other places of shelter. Our fires to-night were made principally of the dry branches of the artemisia, which covered the slopes. It burns quickly, and with a clear oily flame, and makes a hot fire. The hills here are composed of hard, compact mica slate, with veins of quartz.