On the evening of the fifteenth, finding all our stock of meat injured by too long keeping, four men were sent out on horseback to hunt. At the distance of six miles from camp, they found a solitary bison, which they killed, but concluding from its extreme leanness and the ill-savour of the flesh, that the animal was diseased, they took no part of it. On the following morning they returned, bringing nothing. We were now reduced to the necessity of feeding on our scanty allowance of a gill of parched maize per day to each man, this being the utmost that our limited stores would afford. On the 16th of July, we moved from our encampment on Boiling-spring creek, in a south-western direction to the Arkansa. This ride of twenty-eight miles, which we finished without having once dismounted from our horses, occupied about twelve hours of a calm, sultry day, in every respect like the preceding, in which the thermometer in the shade had {229} ranged from 90 to 100°. Our route lay across a tract of low but somewhat broken sandstone, of an uncommonly slaty structure. It is fine-grained, with an argillaceous cement, and of a light gray or yellowish white colour. It contains thin beds of bituminous clay-slate; and we saw scattered on the surface some small crystals of selenite. It is traversed by numerous deep ravines, in which at this time, not a drop of water was to be found. The soil is scanty, and of incurable barrenness. The texture of the rock is so loose and porous as to unfit it for retaining any portion of the water which falls upon it in rains. A few dwarfish cedars and pines are scattered over a surface consisting of a loose dusty soil, intermixed with thin lamellar fragments of sandstone, and nearly destitute of grass or herbage of any kind. Our sufferings from thirst, heat, and fatigue, were excessive, and were aggravated by the almost unlimited extent of the prospect before us, which promised nothing but a continuation of the same dreary and disgusting scenery. Late in the afternoon we arrived at the brink of the precipice which divides the high plains from the valley of the Arkansa; this is here narrow, and so deeply sunk in the horizontal sandstone, that although there are trees of considerable size growing along the river, they do not rise to the level of the surface of the great plain, and from a little distance on either side, the valley is entirely hid. There our thirst and impatience were for some time tantalized with the view of the cool and verdant valley and copious stream of the Arkansa, while we were searching up and down for a place where we could descend the precipice.