The most extensive tract of valley country east of the Mississippi, is that situated within the bluffs of this river, usually denominatf-d the American bottom, extending from the mouth of the Ocoa or Kaskaskias river, northwardly to that of the Missouri. This spacious bottom, although at present elevated much above the range of the highest freshets, is nevertheless alluvial. Its length along the Mississippi is about eiffhty, and its average breadth about four miles. It is generally destitute of a timber growth, excejit along the margin of the river, upon which is a skirt of woodland extending almost from one end of the tract to the other. The alluvion of the American bottom is composed of the rich mud brought down by the turbid Missouri, united with an abundance of vegetable matter yielded by the waters of the Upper Mississippi, which also characterizes the bottoms of this extensive river, from the Missouri downward to its mouth. Upon this bottom are situated the town of Kaskaskia, the villages of Prairie de Rocher, Harrison, Prairie du Pont, Cahokia, and Illinois, together with many other settlements.

On the same side of the river another large tract of valley

land, called the Mississippi bottom, commences a few miles below the mouth of the river Kaskaskias, and extends downward along the Mississippi between fifty and sixty miles, having an average width of about three miles. This tract, in regard to soil and aspect, is of a character similar to that of the American bottom, except that the former is more plentifully stocked with timber.

Besides these, there are numerous other bottoms on the Mississippi, within the limits prescribed for this report, all of which are composed of a rich alluvion. Those in particular, situated below the confluence of the Mississippi and Missouri, are possessed of a soil exceedingly luxuriant, being composed, as before observed, of the rich and fertilizing mud deposited from the water of the Missouri. Most of them are covered with deep and heavy forests of timber, accompanied with a luxuriant under growth of vines, shrubs, grass and other herbage.

The bottoms of the Wabash, Kaskaskias, Illinois, and Hock rivers, are also made up of a rich alluvion of sand and loam, containing a large proportion of vegetable mould. Their surfaces, like those of the Mississippi bottoms, are generally flat, exhibiting tabular elevations or benches, formed by the washing of the rivers at different periods. Large tracts of prairie land are to be met with upon them, but for the most part, the proportion of woodland is amply sufiicient to supply the adjacent country with timber and fuel.

The vallies of these rivers diflfer from that of the Ohio, not only in having a greater width, but also, in being limited on both sides by bluffs stretching along their whole length, and maintaining nearly a parallel direction; whereas the valley of the Ohio is bounded by aprupt hills, irregularly disposed, in some instances, protruding far into the valley, like promontories, and in others, retiring from the river and affording room for bottoms of pretty large extent.

The Ohio bottoms are uniformly clad in deep forests, except where these have been removed by settlers — no prairies worthy of notice making their appearance.

The valley country, from the circumstances already detailed in allusion to the country constituting the second variety, is almost without exception unhealthy. But, at the same time, it appears evident that this evil gradually decreases in proportion to the increase of population, and the consequent advancement of agriculture; for the products of the soil, which the bottoms yield in the greatest profusion.

instead of being left to wither and decay upon the surface, are necessarily consumed in the subsistence of man and beast, in consequence of which, one of the most fruitful causes of pestilential effluvia, viz. vegetable putrefaction is in a very considerable degree, removed.

The prevailing timber growth of the region, comprehending the two sections of country already described, is exhibited in the following list of trees, viz. cotton wood, willow, sycamore, black walnut, pecan, coffee tree, sweet and sour or black gum, red and water elm, hackberry, blue and white ash, linden, yellow and white poplar, catalpa, black and honey locust, buck eye, bur oak, white and black oak, mulberry, box elder, v/hite dogwood, sugar tree, white maple, wild cherry, red oak, hickory, iron wood and hop hornbeam. The foregoing constitute the principal timber growth of the valley country, and are to be met with more or less frequently throughout the whole of it. Red beech is abundant in some parts of the valley of the Ohio, and in those of many of its tributaries. It abounds also in the northerly parts of the states of Ohio and Indiana. Post oak, black-jack, and several other varieties of the oak, also, chesnut, white and shell-bark hickory, persimmon, &c. are sometimes found in the bottoms, but are more prevalent upon the hills and high lands. Pitch pine abounds in many parts of Ohio and Indiana, and generally in the neighbourhood of the Alleghany mountains. White pine occasionally makes its appearance in the northerly parts of Ohio. Red cedar is found in a great variety of places throughout the country, but nowhere in great abundance.

The under- growth of the several tracts of country above considered, includes a great variety of shrubs, vines, brambles, grasses, and other herbage, to be enumerated in a Botanical catalogue daily expected from Dr. James.

The most valuable timber trees are the white, post, and bur oaks, the white and blue ash, the shell bark hickory, the black walnut, the cherry, the locust, chesnut, poplar, mulberry, birch, cotton wood and Imden. The two last mentioned are seldom used when other kinds of timber are to be had. The cotton wood is not only the most abundant timber growth upon the bottoms, but is more widely diffused than any other, and in many places, is the only variety of forest trees that makes its appearance, which, however, is more particularly the case westward of the Mississippi.

III. — Of the country situated between the Mississippi and Missouri rivers.

We next proceed to a consideration of the country west of the Mississippi, and shall begin with that situated between this river and the Missouri. This section contains no mountains, or indeed hills of any considerable magnitude. The term rolling appears to be peculiarly applicable in conveying an idea of the surface of this region, although it is not entirely destitute of abrupt hills and precipices. The aspect of the whole is variegated with the broad vallies of rivers and creeks, and intervening tracts of undulating up-land, united to the vallies by gentle slopes. Its surface is chequered with stripes of wood land situated upon the margins of the water courses, and dividing the whole into extensive parterres. If we except those parts of the section that are contiguous to the Mississippi and MissDuri, at least nineteen-twentieths of the country are completely destitute of a timber growth.

Within the vallies of these two rivers are extensive tracts of alluvial bottom, possessed of a rich soil. The bottoms of the Missouri, in particular, are probably inferior to none within the limits of the United States, in point of fertility. Those of the Mississippi are very rich, but do not exhibit symptoms of so great fecundity as the former. The bottoms of both, on ascending the rivers, become more sandy, and apparently less productive.

The bottoms of the Missouri are, for the most part, clad in a deep and heavy growth of timber and under-brush, to the distance of about three hundred and fifty miles above its mouth There are, however, prairies of considerable extent occasionally to be met with on this part of the river. Higher up the prairies within the river valley, become more numerous and extensive, till at length no woodlands appear, except tracts of small size, situated at the points formed by the meanders of the river.

The bottoms on the Upper Mississippi, (that part of the Mississippi situated above its confluence with the Missouri being distinguished by this appellation) contain less wood land in proportion to their extent, than those of the Missouri. The prairies upon this river also become more numerous and extensive as we proceed upward.

The interior of the country situated between the vallies of these rivers, presents, as before remarked, a rolling aspect, inclining to hilly and broken, in some parts, but generally

variegated with gentle swells and broad vallies. Within this section are numerous small rivers and creeks, with vallies of a character similar to that of the Mississippi or Missouri, but not so fertile. These vallies expand to a great width, compared with the magnitude of the streams upon which they are situated, but are not bounded by abrupt bluffs, like those of the two rivers just mentioned. They are generally covered with a luxuriant growth of grass and other herbage, and occasionally present copses of wood land of moderate extent. The timber growth of the bottoms is similar to that of the Mississippi bottoms, cotton wood, blue and white ash, hackberry, black walnut, cherry, mulberry, hickory and several varieties of the oak being the prevailing timber trees. The hills or high lands are in some instances covered with a scrubby growth of timber and furze, consisting of post oak, black jack, hazle, green briar, &c.

The soil of this section is probably equal if not superior to that of any other tract of upland of equal extent, within our territory. But the scarcity of timber, mill-seats and springs of water, defects that are almost uniformly prevalent, must for a long time prove serious impediments in the way of settling the country.

The population of this section of country is located almost exclusively within the vallies of the Mississippi and Missouri, and in their immediate neighbourhoods; extending upward along the former about one hundred and sixty, and along the latter, about three hundred and twenty miles above their confluence. The most populous parts of the country, are the county of St. Charles, situated near the junction of these two rivers. Cote Sans Des-sein and its vicinity — that part usually denominated the Boon's Lick country, extending from the mouth of Osage river upward, along the Missouri to the river Charaton, and the country on the Mississippi, including the Salt river settlements, which have become numerous and pretty widely diffused.

Along the vallies, both of the Mississippi and Missouri, there are still innumerable vacancies for settlements, holding forth inducements for emigrants to occupy them, equally as strong, as any of the positions already selected. The inhabited portions of this section have, in many instances, proved unhealthy, owing, in all probability, to the same causes that have been herein assigned, in relation to the country east of the Mississippi, which operate with equal force and effect upon the inhabitants of this section.

IV.— 0/" the country situated between the Missouri and Red Rivers, west of th>' Mississippi and east of the Meridian of the Council Bluff.

Although no precise limits can be assigned as the western boundary of this section, yet the meridian above proposed, may be regarded as a line of division between two regions differing in their general character and aspect. It is not pretended that the immediate course of the line is marked by any distinct features of the country, but that a gradual change is observable in the general aspect of the two regions, which takes place in the vicinity of the proposed line. The assumed meridian is in longitude ninety- six degrees west, ntarlj', and crosses the Platte a few miles above its mouth — the Konzas near the junction of its principal forks — the Arkansa about one hundred miles above the Verdigris or seven hundred miles from its mouth — the Canadian, about one hundred and fifty miles from its mouth, and the Red river about one hundred and fifty miles above the Kiamisha river.