The Gasconade, Osage, and Konzas rivers are navigable in the spring season, but their navigation seldom extends far inland from their mouths, being obstructed by shoals or rapids.
Of the rivers tributary to the Missouri, it is remarkable that their mouths are generally blocked up with mud, consequent to the subsidence of the summer freshet of that river, which usually takes place in the month of July. The reason is obvious; the freshets of the more southerly tributaries are discharged early in the season, and wash from their mouths the sand and mud previously deposited therein, leaving them free from obstructions. These freshets having subsided, the more northerly branches discharge their floods, formed by the melting of the snow at a later period. The Missouri being swollen thereby, backs its waters, charged with mud, considerable distances up the mouths of the tributaries before alluded to. The water here becoming stagnant, deposits its mud; and the tributaries, having no more freshets to expel it, remain with their mouths thus obstructed till the ensuing spring.
The lower part of the Canadian river, although it is included within the section under consideration, will be described in the sequel of the report, in connexion with the rest of that river.
Of the animals found in the several sections of country above described, there are a great variety in almost every department of zoology. But as most of them are common in other parts of the United States, they need not to be enumerated here.
{223} Of the country situated between the meridian of the Council Bluff and the Rocky Mountains
We next proceed to a description of the country westward of the assumed meridian, and extending to the Rocky Mountains, which are its western boundary. This section embraces an extent of about four hundred miles square, lying between 96 and 105 degrees of west longitude, and between 35 and 42 degrees of north latitude.
Proceeding westwardly across the meridian above specified, the hilly country gradually subsides, giving place to a region of vast extent, spreading towards the north and south, and presenting an undulating surface, with nothing to limit the view or variegate the prospect, but here and there a hill, knob, or insulated tract of table-land. At length the Rocky Mountains break upon the view, towering abruptly from the plains, and mingling their snow-capped summits with the clouds.
On approaching the mountains, no other change is observable in the general aspect of the country, except that the isolated knobs and table-lands above alluded to become more frequent and more distinctly marked, the bluffs by which the valleys of watercourses are bounded present a greater abundance of rocks, stones lie in greater profusion upon the surface, and the soil becomes more sandy and sterile. If, to the characteristics above intimated, we add that of an almost complete destitution of woodland (for not more than one thousandth part of the section can be said to possess a timber-growth) we shall have a pretty correct idea of the general aspect of the whole country.
The insulated tracts herein alluded to as table-lands, are scattered throughout the section, and give to the country a very remarkable appearance. They rise from six to eight hundred feet above the common {224} level, and are surrounded in many instances by rugged slopes and perpendicular precipices, rendering their summits almost inaccessible. Many of them are in this manner completely insulated, while others are connected with the plains below by gentle acclivities, leading from their basis to their summits, upon one side or other of each eminence. These tracts, as before intimated, are more numerous, but less extensive in the vicinity of the Rocky Mountains than they are farther eastward; and in the former situations, they are more strikingly characterized by the marks above specified than in the latter.