Col. Fremont, in his narrative, gives the following account of a perilous adventure of himself and party, in attempting to run a canon, on the river Platte. They had previously passed three cataracts:

We reËmbarked at nine o'clock, and, in about twenty minutes, reached the next canon. Landing on a rocky shore at its commencement, we ascended the ridge to reconnoiter. Portage was out of the question. So far as we could see, the jagged rocks pointed out the course of the canon, on a winding line of seven or eight miles. It was simply a narrow, dark chasm in the rock; and here the perpendicular faces were much higher than in the previous pass, being at this end two to three hundred, and further down, as we afterward ascertained, five hundred feet in vertical height.

Our previous success had made us bold, and we determined again to run the canon. Every thing was secured as firmly as possible; and, having divested ourselves of the greater part of our clothing, we pushed into the stream. To save our chronometer from accident, Mr. Preuss took it, and attempted to proceed along the shore on the masses of rock, which, in places, were piled up on either side; but, after he had walked about five minutes, every thing like shore disappeared, and the vertical wall came squarely down into the water. He therefore waited until we came up.

An ugly pass lay before us. We had made fast to the stern of the boat a strong rope about fifty feet long; and three of the men clambered along among the rocks, and, with this rope, let her slowly through the pass. In several places, high rocks lay scattered about in the channel; and, in the narrows, it required all our strength and skill to avoid staving the boat on the sharp points. In one of these, the boat proved a little too broad, and stuck fast for an instant, while the water flew over us; fortunately, it was but for an instant, as our united strength forced her immediately through. The water swept overboard only a sextant and a pair of saddle-bags. I caught the sextant as it passed by me; but the saddle-bags became the prey of the whirlpools. We reached the place where Mr. Preuss was standing, took him on board, and, with the aid of the boat, put the men with the rope on the succeeding pile of rocks.

We found this passage much worse than the previous one, and our position was rather a bad one. To go back was impossible; before us, the cataract was a sheet of foam; and, shut up in the chasm by the rocks, which, in some places, seemed almost to meet overhead, the roar of the water was deafening, We pushed off again; but, after making a little distance, the force of the current became too great for the men on shore, and two of them let go the rope. Lajeunesse, the third man, hung on, and was jerked headforemost into the river, from a rock about twelve feet high; and down the boat shot, like an arrow, Bazil following us in the rapid current, and exerting all his strength to keep in mid channel--his head only seen occasionally like a black spot in the white foam. How far we went, I do not exactly know; but we succeeded in turning the boat into an eddy below. "'Cre Dieu," said Bazil Lajeunesse, as he arrived immediately after us, "Je crois bien que j'ai nage un demi mile." He had owed his life to his skill as a swimmer, and I determined to take him and two others on board, and trust to skill and fortune to reach the other end in safety. We placed ourselves on our knees, with the short paddles in our hands, the most skillful boatman being at the bow; and again we commenced our rapid descent. We cleared rock after rock, and shot past fall after fall, our little boat seeming to play with the cataract. We became flushed with success, and familiar with danger; and, yielding to the excitement of the occasion, broke forth into a Canadian boat-song. Singing, or rather shouting, we dashed along, and were, I believe, in the midst of the chorus, when the boat struck a concealed rock immediately at the foot of a fall, which whirled her over in an instant. Three of my men could not swim, and my first feeling was to assist them, and save some of our effects; but a sharp concussion or two convinced me that I had not yet saved myself. A few strokes brought me into an eddy, and I landed on a pile of rocks on the left side. Looking around, I saw that Mr. Preuss had gained the shore on the same side, about twenty yards below; and a little climbing and swimming soon brought him to my side. On the opposite side, against the wall, lay the boat, bottom up; and Lambert was in the act of saving Descoteaux, whom he had grasped by the hair, and who could not swim.

For a hundred yards below, the current was covered with floating books and boxes, bales and blankets, and scattered articles of clothing; and so strong and boiling was the stream, that even our heavy instruments, which were all in cases, kept on the surface, and the sextant, circle, and the long, black box of the telescope, were in view at once. For a moment, I felt somewhat disheartened. All our books--almost every record of the journey--our journals and registers of astronomical and barometrical observations--had been lost in a moment, But it was no time to indulge in regrets; and I immediately set about endeavoring to save something from the wreck. Making ourselves understood as well as possible by signs, (for nothing could be heard in the roar of the waters,) we commenced our operations. Of every thing on board, the only article that had been saved was my double-barreled gun, which Descoteaux had caught and clung to with drowning tenacity. The men continued down the river on the left bank. Mr. Preuss and myself descended on the side we were on; and Lajeunesse, with a paddle in his hand, jumped on the boat alone, and continued down the canon. She was now light, and cleared every bad place with much less difficulty. In a short time he was joined by Lambert and the search was continued for about a mile and a half, which was as far as the boat could proceed in the pass.

Here the walls were about five hundred feet high, and the fragments of rocks from above had choked the river into a hollow pass, but one or two feet above the surface. Through this, and the interstices of the rock, the water found its way. Favored beyond our expectations, all our registers had been recovered, with the exception of one of my journals, which contained the notes and incidents of travel, and topographical descriptions, a number of scattered astronomical observations, principally meridian altitudes of the sun, and our barometrical register west of Laramie. Fortunately, our other journals contained duplicates of the most important barometrical observations. In addition to these, we saved the circle; and these, with a few blankets, constituted every thing that had been rescued from the waters.