Of the rivers of this region there are many that are navigable for keel-boats of several tons burden, but all of them have more or less obstructions from shoals and frosts at different periods. The Arkansa, which, in point of magnitude and extent, deservedly ranks second amongst the tributaries of the Mississippi (the Missouri being the first), is navigable to the mouth of the Neosho, or Grand river, a distance of about six hundred miles. In this part of the river, however, the navigation is liable to obstructions, for want of a sufficient depth of water, during a period of two and a half or three months, commencing in July. Occasional obstructions are also imposed by ice forming in the river during the winter season, but these are seldom of long continuance, the winters being usually short and mild. As the freshets {221} of the river seldom prevail more than a few days at a time, and are usually attended by sudden rises and falls of the water, boats of moderate draft and burden only are suited to its navigation. The Arkansa is navigable at all seasons for boats of this description about two hundred miles, which comprehends the distance by the meanders of the river from the Mississippi to the commencement of the high lands. Above the mouth of the Neosho it spreads to a much greater width than below, and the water is more extensively diffused over its bed, which renders the shoals more numerous and the navigation more precarious. This part of the Arkansa cannot indeed be considered navigable, even for pirogues of a large size, except during the short period of a freshet, which is seldom long enough to complete a voyage of one hundred miles ascending and descending. The Red river is navigable, during most of the year, to the Great Raft, about five hundred miles from its mouth. At this place its navigation is effectually obstructed, except in a high stage of water, when keel-boats of ten or fifteen tons burden may pass around it and ascend several hundred miles above. That part of the river situated above the Raft, however, like the upper part of the Arkansa, is rendered impassable for boats of burden, by shoals and sand-bars.