These licks exist in various parts of the country. They are marshy swamps in which saline springs break out, and are frequented by buffalo, deer, and other wild animals, for the sake of the salt with which in the summer they are incrusted, and which in winter is dissolved in the mud. Wild beasts, as well as cattle, greedily devour this incrustation, and will burrow into the clay impregnated with salt in order to lick the mud. In the Big-Bone Lick of Kentucky the bones of a vast number of mastodons and other extinct quadrupeds have been dug up.
This celebrated bog is situated in a nearly level plain, bounded by gentle slopes, which lead up to wide-extended table-lands. In the spots where the salt springs rise, the bog is so soft that a man may force a pile into it many yards perpendicularly. Some of these quaking bogs are even now more than fifteen acres in extent, but were formerly much larger, before the surrounding forest was partially cleared away. Even at the present day cows, horses, and other quadrupeds are occasionally lost here, as they venture on to the treacherous ground. It may be easily understood, therefore, how the vast mastodons, elephants, and other huge animals lost their lives. In their eagerness to drink the saline waters, or lick the salt, those in front, hurrying forward, would have been pressed upon by those behind, and thus, before they were aware of their danger, sank helplessly into the quagmire. It is supposed that the bones of not less than one hundred mastodons and twenty elephants have been dug up out of the bog, besides which the bones of a stag, extinct horse, megalonyx, and bison, have been obtained. Undoubtedly, therefore, this plain has remained unchanged in all its principal features since the period when these vast extinct quadrupeds inhabited the banks of the Ohio and its tributaries. Here and there the Big-bone Lick is covered with mud, washed over it by some unusual rising of the Ohio River, which is known to swell sixty feet above its summer level.
Passing on through wide-spreading prairies, we cross the mighty stream of the Mississippi to a slightly elevated district of broad savannahs, till we reach a treeless region bordering the very foot of the Rocky Mountains. Through this region numerous rivers pass on their way to the Mississippi. Leaving at length the great western plain, we begin to mount the slopes of the Rocky Mountains, when we may gaze upwards at the lofty snow-covered peaks above our heads. Hence, crossing the mighty range in spite of grizzly bears and wilder Indians, we descend towards the bank of the Rio Colorado, which falls into the Gulf of California, and thence over a mountainous region, some of whose heights, as Mount Dana, reach an elevation of 13,000 feet, and Mount Whitney, 15,000 feet.
The Fourth Zone.
The southernmost of the four zones begins on the coast of Florida, passes for hundreds of miles over a low or gently sloping country toward the great western plains which border the Rocky Mountains into Texas; its southern boundary being the Gulf of Mexico. Through this region flow numerous rivers, the queen of which is the Mississippi. The western portion is often wild and barren in the extreme, inhabited only by bands of wild and savage Indians. The Rocky Mountains being passed, there is a lofty table-land, and then rise the Sierras de los Nimbres and Madre; beyond which, bordering the Gulf of California, is the wild, grandly picturesque province of Sonora, with its gigantic trees and stalactite caves.
Part 1—Chapter III.
The Prairies, Plains of the West, and Passes of the Rocky Mountains.
To obtain, however, a still more correct notion of the appearance of the continent, we must take another glance over it. We shall discover, to the north, and throughout the eastern portion where civilised man has not been at work dealing away the trees, a densely-wooded region. Proceeding westward, as the valley of the Mississippi is approached the underwood disappears, and oak openings predominate. These Oak Openings, as they are called, are groves of oak and other forest-trees which are not connected, but are scattered over the surface at a considerable distance from one another, without any low shrub or underbrush between them.