9th.--This morning we caught the first faint glimpse of the Rocky mountains, about sixty miles distant. Though a tolerably bright day, there was a slight mist, and we were just able to discern the snowy summit of "Long's peak," ("_les deux oreilles_" of the Canadians,) showing like a cloud near the horizon. I found it easily distinguishable, there being a perceptible difference in its appearance from the white clouds that were floating about the sky. I was pleased to find that among the traders the name of "Long's peak" had been adopted and become familiar in the country. In the ravines near this place, a light brown sandstone made its first appearance. About 8, we discerned several persons on horseback a mile or two ahead, on the opposite side of the river. They turned in towards the river, and we rode down to meet them. We found them to be two white men, and a mulatto named Jim Beckwith, who had left St. Louis when a boy, and gone to live with the Crow Indians. He had distinguished himself among them by some acts of daring bravery, and had risen to the rank of chief, but had now, for some years, left them. They were in search of a band of horses that had gone off from a camp some miles above, in charge of Mr. Chabonard. Two of them continued down the river, in search of the horses, and the American turned back with us, and we rode on towards the camp. About eight miles from our sleeping-place, we reached Bijou's fork, an affluent of the right bank. Where we crossed it, a short distance from the Platte, it has a sandy bed about four hundred yards broad; the water in various small streams, a few inches deep. Seven miles further brought us to the camp of some four or five whites, (New Englanders, I believe,) who had accompanied Captain Wyeth to the Columbia river, and were independent trappers. All had their squaws with them, and I was really surprised at the number of little fat, buffalo-fed boys that were tumbling about the camp, all apparently of the same age, about three or four years old. They were encamped on a rich bottom, covered with a profusion of rich grass, and had a large number of fine-looking horses and mules. We rested with them a few minutes, and in about two miles arrived at Chabonard's camp, on an island in the Platte. On the heights above, we met the first Spaniard I had seen in the country. Mr. Chabonard was in the service of Bent and St. Vrain's company, and had left their fort some forty or fifty miles above, in the spring, with boats laden with the furs of the last year's trade. He had met the same fortune as the voyageurs on the North fork; and, finding it impossible to proceed, had taken up his summer's residence on this island, which he had named St. Helena. The river hills appeared to be composed entirely of sand, and the Platte had lost the muddy character of its waters, and here was tolerably clear. From the mouth of the South fork, I had found it occasionally broken up by small islands; and at the time of our journey, which was at a season of the year when the waters were at a favorable stage, it was not navigable for any thing drawing six inches water. The current was very swift--the bed of the stream a coarse gravel. From the place at which we had encountered the Arapahoes, the Platte had been tolerably well fringed with timber, and the island here had a fine grove of very large cottonwoods, under whose broad shade the tents were pitched. There was a large drove of horses in the opposite prairie bottom; smoke was rising from the scattered fires, and the encampment had quite a patriarchal air. Mr. C. received us hospitably. One of the people was sent to gather mint, with the aid of which he concocted very good julep; and some boiled buffalo tongue, and coffee with the luxury of sugar, were soon set before us. The people in his employ were generally Spaniards, and among them I saw a young Spanish woman from Taos, whom I found to be Beckwith's wife.