CHAPTER II.—VALLEYS.
THE Valley of the Mississippi is the largest in the world; and differs from any other of very great extent, in the peculiar distinctness of its outline. It is bounded south by the gulf of Mexico, west by the Rocky Mountains, north by the great lakes of British America, and east by the Apalachian Mountains. Its general surface may be classed under three distinct aspects; the thickly timbered, the barren, and the prairie country. This valley extends from the twenty-ninth to the forty-ninth parallel of north latitude, and exhibits every variation of temperature from the climate of Canada to that of Louisiana. It is a wide extent of level country, in which the various rivers, inclosed between two chains of mountains three thousand miles apart, find a common centre, and discharge their waters into the sea by a single channel. Geologically considered, this immense valley presents every where the aspect of what is called secondary formation. Its prevailing rocks are carbonate of lime, disposed in the most regular lamina, masses of limestone, in which seashells or organic remains are imbedded, retaining their distinct and original form. At every step, is presented the aspect of a country once covered by lakes or seas. The soil, stones, and exuviæ of lake or river formation, are, to all appearance, of comparatively recent origin. In the alluvial soils, to the depth of from twenty to an hundred feet, are found pebbles, smoothed by the evident attrition of waters, having the appearances of those masses of smoothed pebbles that are thrown on the seashore by the dashing of the surge. Leaves, branches, and logs are also found at great distances from the points where wood is seen at present, and at great depths below the surface. In the most solid blocks of limestone, split for building, deers’ horns and other animal exuviæ are found incorporated in the solid stone.
‘From its character of recent formation,’ says Mr. Flint, ‘from the prevalence of limestone every where, from the decomposition which it has undergone, and is constantly undergoing, from the prevalence of decomposed limestone in the soil, probably, results another general attribute of this valley—its character generally for uncommon fertility. We would not be understood to assert, that the country is every where alike fertile. It has its sterile sections. There are here, as elsewhere, infinite diversities of soil, from the richest alluvions, to the most miserable flint knobs; from the tangled cane brakes, to the poorest pine hills. There are, too, it is well known, towards the Rocky Mountains, wide belts that have a surface of sterile sands, or only covered with a sparse vegetation of weeds and coarse grass. But of the country in general, the most cursory observer must have remarked, that, compared with lands, apparently of the same character in other regions, the lands here obviously show marks of singular fertility. The most ordinary, third rate, oak lands, will bring successive crops of wheat and maize, without any manuring, and with but little care of cultivation. The pine lands of the southern regions are in many places cultivated for years, without any attempts at manuring them. The same fact is visible in the manner in which vegetation in this country resists drought. It is a proverb on the good lands, that if there be moisture enough to bring the corn to germinate, and come up, they will have a crop, if no more rain falls until the harvest. We have a thousand times observed this crop continuing to advance towards a fresh and vigorous maturity, under a pressure of drought, and a continuance of cloudless ardor of sun, that would have burned up and destroyed vegetation in the Atlantic country.
‘We have supposed this fertility to arise, either from an uncommon proportion of vegetable matter in the soil; from the saline impregnations mixed with the earth, as evidenced in the numberless licks, and springs of salt water, and the nitrous character of the soil, wherever, as in caves, or under buildings, it is sheltered from moisture; or, as we have remarked, from the general diffusion of dissolved limestone, and marly mixtures over the surface. In some way, spread by the waters, diffused through the soil, or the result of former decomposition, there is evidently much of the quickening and fertilizing power of lime mixed with the soil.’
The greatest length of the Valley of the Missouri is twelve hundred miles, its greatest breadth seven hundred. In the direction of the western rivers, the inclined plain of the Missouri extends eight hundred miles from the Chippewayan Mountains, and rather more than that distance from south to north, from the southern branches of the Kansas, to the extreme heads of the northern confluents of the valley. 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 mountains partake of these traits of desolation.
The celebrated valley called the American Bottom extends along the eastern bank of the Mississippi to the Piasa Hills, four miles above the mouth of the Missouri. It is several miles in width, and has a soil of astonishing fertility. It has all the disadvantages attending tracts of recent alluvion, the most valuable parts of it being liable to be swept away by the current of the Mississippi. ‘But the inexhaustible fertility of its soil,’ says Major Long, ‘makes amends for the insalubrity of the air, and the inconvenience of a flat and marshy situation, and this valley is undoubtedly destined to become one of the most populous parts of America. We were formerly shown here a field that had been cultivated, without manure, one hundred years in succession, and which when we saw it, (in August, 1816,) was covered with a very luxuriant growth of corn.’
The Ohio Valley is divided by the river into two unequal sections, leaving on the north-west side eighty thousand, and on the south-east one hundred and sixteen thousand square miles. The river flows in a deep ravine five hundred and forty-eight miles long in a straight line, and nine hundred and ninety-eight by the windings of the stream. In its natural state the Ohio valley, with the exception of the central plain, was covered with a dense forest. Open savannahs commence as far east as the sources of the Muskingum. Like the plain itself, those savannahs expand to the westward, and on the Illinois open into immense prairies. This valley may be regarded as a great plain inclining from the Apalachian system of the north-west, obliquely and deeply cut by the Ohio and its numerous confluents, into chasms from an elevation of four hundred feet to nearly the level of the streams. On the higher parts of the valley, the banks of the river rise by bold acclivities which wear almost a mountainous aspect. This boldness of outline imperceptibly softens in descending the Ohio, and on approaching the Mississippi, an extent of level woodland bounds the horizon. Ascending the rivers of the south-east slope, the scenery becomes more and more rugged, until it terminates in the ridges of the Apalachian chains: if the rivers of the north-west slope are followed, on the contrary, we find the landscape broken and varied near the Ohio, but around their sources flat and monotonous.
The Valley of the Hudson varies extremely in its width, being in some places contracted to the immediate neighborhood of the stream; in others extending forty miles. On the borders of the river the land is generally elevated. The Mohawk is bordered by two long ranges of hills presenting little variety of aspect. In the early part
