On the twentieth, near an Indian camp, the voyagers observed a scaffold, about seven feet high, on which were two sleds, with their harness; and under the scaffold was the body of a female, carefully wrapped in several dressed buffalo-skins. Near it lay a bag, made of buffalo-skin, and containing some articles of apparel, scrapers for dressing hides, some dried roots, plats of sweet grass, and a small quantity of tobacco. These, as well as the body, had probably fallen down by accident, as it is customary to place the dead bodies on scaffolds. At a little distance was the body of a dog, not yet decayed: he had, no doubt, been employed in dragging, in the sled, the body of his mistress, and, according to the Indian usage, had been sacrificed to her. From the sand-bars in the river, the wind sometimes blew such vast quantities of sand into the air, as to appear like clouds, and even to conceal the opposite bank from view. These clouds of sand floated, like columns of thick smoke, to the distance of many miles; and the particles were so penetrating, that nothing could be kept free from them. Near the junction of _Yellow-stone river_ with the Missouri, the country was much more woody than it had been in any other part, since the voyagers had passed the Chayenne; and the trees were chiefly of cotton-wood, elm, ash, box, and alder. In the low grounds were rose-bushes, the red-berry, service-berry, red-wood, and other shrubs; and among the bushes on the higher plains, were observed willows, gooseberry-trees, purple currant-trees, and honeysuckles. The sources of Yellow-stone river are said to be in the Rocky Mountains, near those of the Missouri and the Platte; and this river is navigable, in canoes, almost to its head. Near the junction of the Yellow-stone and Missouri rivers, there is a high plain, which extends three miles in width, and seven or eight miles in length; and which Captain Lewis says might be rendered a very advantageous station for a trading establishment. Beyond this place, the hills were rough and high, and almost overhung the river. As the voyagers advanced, the low grounds were fertile and extensive, with but little timber, and that cotton-wood. On the 3d of May, they reached the mouth of a river, which; from the unusual number of porcupines that were seen near it, they called _Porcupine river_. For several days after this, they continued their progress without much interruption. In many places the river was, at least, half a mile wide. During their excursions on the shore, in pursuit of food, they encountered many perils in shooting at bears. Some of these were of vast size and strength: one of them weighed nearly six hundred pounds, and measured eight feet seven inches and a half, from the nose to the extremity of the hind feet. Beyond the _Muscle-shell river_, which the voyagers reached on the 21st, the shores of the Missouri were abrupt and bold, and composed of a black and yellow clay.