Ohio River. The Ohio river is formed by the junction of the Alleghany and Monongahela, at Pittsburg. The Alleghany river rises not far from the head of the western branch of the Susquehannah, in the highlands of McKean county, Pennsylvania. It runs north till it penetrates Cataraugus county, New York, then turns west, then southwest, and finally takes a southern course to Pittsburg. It receives a branch from the Chatauque lake, Chatauque county, New York. The Monongahela rises near the sources of the Kenhawa, in western Virginia, and runs north till it meets the Alleghany.

The general course of the Ohio is southwest. Its current is gentle, and it receives a number of tributaries, which are noticed in the States where they run.

The Valley of the Mississippi has been arranged by Mr. Darby, into four great subdivisions.

1. The Ohio Valley, length 750 miles, and mean width 261; containing 196,000 square miles.

2. Mississippi Valley, above Ohio, including the minor valley of Illinois, but exclusive of Missouri, 650 miles long, and 277 mean width, and containing 180,000 square miles.

3. Lower Valley of the Mississippi, including White, Arkansas, and Red river vallies, 1,000 miles long, and 200 wide, containing 200,000 square miles.

4. Missouri proper, including Osage, Kansau, Platte rivers, &c. 1,200 miles long, and 437 wide, containing 523,000 square miles.

"The Valley of the Ohio is better known than any of the others; has much fertile land, and much that is sterile, or unfit for cultivation, on account of its unevenness. It is divided into two unequal portions, by the Ohio river; leaving on the right or northwest side 80,000, and on the left or southeast side, 116,000 square miles. The eastern part of this valley is hilly, and rapidly acclivous towards the Appalachian mountains. Indeed its high hills, as you approach these mountains, are of a strongly marked mountainous character. Of course the rivers which flow into the Ohio--the Monongahela, Kenhawa, Licking, Sandy, Kentucky, Green, Cumberland, and Tennessee--are rapid, and abounding in cataracts and falls, which, towards their sources, greatly impede navigation. The western side of this Valley is, also, hilly for a considerable distance from the Ohio, but towards its western limit, it subsides to a remarkably level region. So that whilst the eastern line of this Valley lies along the high table land, on which the Appalachian mountains rest, and where the rivers of the eastern section of this Valley rise, which is at least 2,000 miles generally above the ocean level; the western line has not an elevation of much more than half of that amount on the north, and which greatly subsides towards the Kaskaskia. The rivers of the western section are Beaver, Muskingum, Hockhocking, Scioto, Miami, and Wabash. Along the Ohio, on each side, are high hills, often intersected with deep ravines, and sometimes openings of considerable extent, and well known by the appellation of "Ohio hills." Towards the mouth of the Ohio, these hills almost wholly disappear, and extensive level bottoms, covered with heavy forests of oak, sycamore, elm, poplar, and cotton wood, stretch along each side of the river. On the lower section of the river, the water, at the time of the spring floods, often overflows these bottoms to a great extent. This fine Valley embraces considerably more than one half of the whole population of the entire Valley of the West. The western parts of Pennsylvania and Virginia, the entire states of Ohio, Indiana, and Kentucky, the larger part of Tennessee, and a smaller part of Illinois, are in the Valley of the Ohio."

The Upper Valley of the Mississippi possesses a surface far less diversified than the Valley of the Ohio. The country where its most northern branches take their rise, is elevated table land, abounding with marshes and lakes, that are filled with a graniferous vegetable called wild rice. It is a slim, shrivelled grain of a brownish hue, and gathered by the Indians in large quantities for food. There are tracts of arable land covered with elm, linden, pine, hemlock, cherry, maple, birch and other timber common to a northern climate. From the same plateau flow the numerous branches of Red river, and other streams that flow into lake Winnipeck, and thence into Hudson's bay. Here, too, are found some of the head branches of the waters of St. Lawrence, that enter the Lake of the Woods, and Superior. In the whole country of which we are speaking, there is nothing that deserves the name of mountain. Below the falls of St. Anthony the river bluffs are often abrupt, wild and romantic, and at their base and along the streams are thousands of quartz crystals, carnelians and other precious stones.

But a short distance in the rear, you enter upon table land of extensive prairies, with clumps of trees, and groves along the streams. Further down, abrupt cliffs and overhanging precipices are frequently seen at the termination of the river alluvion.

The whole country northwest of the Ohio and east of the Mississippi, as far north as the falls of St. Anthony, exhibits striking marks of a diluvial formation, by a gradual retiring of the waters. From the summit level that divides the waters of the lakes from those of the Mississippi, through Ohio, Indiana, Illinois, and Wisconsin, which is scarcely a perceptible ridge, to the south point of Illinois at the junction of the Ohio and Mississippi, appears to have once been a plane with an inclination equal to 12 or 15 inches per mile. The ravines and vallies appear to have been gradually scooped out by the abrasion of the waters.

"The Lower Mississippi Valley, has a length of 1,200 miles, from northwest to southeast, considering the source of the Arkansas, and the mouth of the Mississippi river as extreme points; reaching from north latitude 29 deg. to 42 deg., and without estimating mountains, ridges, or peaks, differs in relative elevation at least 500 feet.

"The Arkansas river rises near north latitude 42 deg., and longitude 32 deg. west from Washington, and falls into the Mississippi at 33 deg. 56', passing over eight degrees of latitude.

"Red River rises in the mountainous country of Mexico, north of Texas, in north latitude 34 deg.; and west longitude 28 deg. from Washington, and falls into the Mississippi in latitude 31 deg. They are both remarkable rivers for their extent, the number of their branches, the volume of their waters, the quantity of alluvion they carry down to the parent stream, and the color of their waters. Impregnated by saline particles, and colored with ocherous earth, the waters of these two rivers are at once brackish and nauseous to the taste, particularly near their mouths; that of Red river is so much so at Natchitoches at low water that it cannot be used for culinary purposes.

"At a short distance below the mouth of the Red river, a large bayou, (as it is called,) or outlet, breaks from the Mississippi on the west; by which, it is believed, that as large a volume of water as the Red river brings to the parent river, is drained off, and runs to the gulf of Mexico, fifty miles from the mouth of the Mississippi. The name of this bayou is Atchafalaya, or as it is commonly called, Chaffalio. Below this bayou, another of large dimensions breaks forth on the same side, and finally falls into the Atchafalaya. This is the Placquemine. Still lower, at Donaldsonville, ninety miles above New Orleans, on the same side, the Lafourche bayou breaks out, and pursues a course parallel to the Mississippi, fifty miles west of the mouth of that river. On the east side, the Ibberville bayou drains off a portion of the waters of the Mississippi, into lakes Maurepas, Ponchartrain, Borgnes, and the gulf of Mexico, and thus forms the long and narrow island of Orleans.

"In the lower Valley of the Mississippi there is a great extent of land of the very richest kind. There is also much that is almost always overflown with waters, and is a perpetual swamp. There are extensive prairies in this Valley; and towards the Rocky mountains; on the upper waters of the Arkansas and Red rivers, there are vast barren steppes or plains of sand, dreary and barren, like the central steppes of Asia. On the east of the Mississippi, are extensive regions of the densest forests, which form a striking contrast with the prairies which stretch on the west of that great river.

"The Valley of the Missouri extends 1200 miles in length, and 700 in width, and embraces 253,000 square miles. The Missouri river rises in the Chippewan mountains, through eight degrees, or nearly 600 miles. The Yellow Stone is its longest branch. The course of the Missouri, after leaving the Rocky mountains, is generally southeast, until it unites with the Mississippi. The principal branches flow from the southwest. They are the Osage, Kansas, Platte, &c. The three most striking features of this Valley are, 1st. The turbid character of its waters. 2d. The very unequal volumes of the right and left confluences. 3d. The immense predominance of the open prairies, over the forests which line the rivers. The western part of this Valley rises to an elevation towards the Chippewan mountains, equal to ten degrees of temperature. Ascending from the lower verge of this widely extended plain, wood becomes more and more scarce, until one naked surface spreads on all sides. Even the ridges and chains of the Chippewan, partake of these traits of desolation. The traveller, who has read the descriptions of central Asia, by Tooke or Pallas, will feel on the higher branches of the Missouri, a resemblance, at once striking and appalling; and he will acknowledge, if near to the Chippewan mountains in winter, that the utmost intensity of frost over Siberia and Mongolia, has its full counterpart in North America, on similar, if not on lower latitudes. There is much fertile land in the Valley of the Missouri, though much of it must be forever the abode of the buffalo and the elk, the wolf and the deer.[2]