about one thousand feet high, which extended far in both directions athwart our course. It was the edge of the Uinta Mountains. At its very foot the river seemed to stop. It could be seen neither to right nor, to left, nor could any opening be detected in the mountain, except high up where Powell pointed out to us a bare patch of brilliant red rocks saying it was the top of Flaming Gorge, the beginning of the canyon series. Passing the mouth of Henry’s Fork on the right, the river doubled suddenly to the left between two low cliffs, where there was a small whirlpool, which I take to be the “Green River Suck” of Ashley and the early trappers. Around another point we swept and found ourselves floating on the tranquil waters of Flaming Gorge. A fine grove of deep green cottonwoods stood out on the left in contrast to the rough red rocks. There were moored the other boats, which on this occasion had preceded us, and the ever-faithful Andy was engaged in preparing dinner. The next and first real canyon was the one called Horseshoe, a short and beautiful gorge some sixteen hundred feet in depth, and containing rapid “Number One,” a very mild affair, but particularly noticeable because it is the first of the six hundred, great and small, we had the satisfaction of vanquishing in our war against the falling waters. We had already descended something over one hundred and fifty of the five thousand feet we expected to go down, but there had been only swift water at that stage of flood; nothing that, on the Colorado, would be considered a serious rapid. Green River Valley. Camp at Tilted Ledge near Henry’s Fork. Green River Valley. Camp at Tilted Ledge near Henry’s Fork. Photograph by E.O. BEAMAN, U.S. Colo. Riv. Exp. Every morning the cabins of the boats were packed like so many trunks. The blankets were rolled up and put in their rubber cases, all bags of supplies were securely tied and stowed away, in short, every article was placed in the cabins and the hatches firmly buttoned in place, with the canvas cover drawn snugly over the deck. Only a grand smash-up could injure these things. Nothing was left out but such instruments as were hourly needed, the guns, life-preservers, and a camp-kettle in each boat for bailing purposes. On each of two boats there was a topographer, whose duty was to sight the direction of every bend of the river and estimate the length of the stretch. Thompson, on his boat, also kept a similar record. The sighting was done with a prismatic compass, and one of these was rendered more interesting by bearing on the leather case the name of George B. McClellan, written by the future general when he was a lieutenant of engineers. There was seldom much discrepancy between the different estimates made during the day, as men grow very accurate in such matters, but a check on all estimates was obtained by frequent observations for latitude and longitude.