The _River Osage_, so called from the well known tribe of Indians inhabiting its banks, enters the Missouri one hundred and thirty-three miles above its confluence with the Mississippi. Its sources are in the Ozark Mountains. Flowing along the base of the north-western slope of a mountainous range, it receives from the east several rapid and beautiful tributaries. In point of magnitude this river ranks with the Cumberland and Tennessee. It has been represented as navigable for six hundred miles, but this Major Long considers an exaggeration, on account of the great number of shoals and sand-bars in its current. In the lower part of its course it traverses broad and fertile bottom-lands, bearing heavy forests of sycamore and cotton trees. _Charaton River_ is seventy-five yards wide at its mouth, and navigable at high water one hundred and fifty miles. Half a mile from its confluence with the Missouri, it receives the _Little Charaton_, also a considerable stream, and navigable for many miles. The Charaton has its source near the De Moyen river of the Mississippi, and traverses a country which is of great importance, both on account of the fertility of its soil, and its inexhaustible mines of gold. The _Arkansas River_ rises in the Rocky Mountains in north latitude forty-two degrees, near the borders of the territory of the United States and Mexico. It is about two thousand miles in length, running in a direction east south-east. Tributary streams are little known; they are remarkable for being deeply impregnated with salt. That part of Arkansas that traverses the Missouri territory is skirted, in great part, by extensive prairies. Spurs of the Masserne Mountains often reach the river. It may be remarked as singular, that to the extent of upwards of three hundred miles in the lower part of the Arkansas, its valley is confined merely to the stream of the river; the waters of the Washita on one side, and White river on the other, rising almost from the very margin of the Arkansas. The land upon the Arkansas, in the Missouri territory, is in great part alluvial; and where not subject to overflow, excellent. The timber corresponds nearly to that of the state of Mississippi, in similar relative situations.