With respect to the geological formation of the soil, it appears chiefly to consist of clay, sand, and sand-stone. All the chains of hills which traverse the prairie, and of which there is one along both the banks of the Missouri, consist of clay mixed with sand, and of sand-stone, with many impressions and petrifactions of shell-fish, and the singular baculites, which are found everywhere on the Missouri and its tributaries, and even here and there in the beds of the streams. Fossil bones are frequently found, and, in the calcareous rock further down the Missouri, entire skeletons, twelve, fourteen, or even more, feet in length, of reptiles of the crocodile kind, of which I brought back one, found in the vicinity of the Big Bend, for which I am indebted to the kindness of Major O'Fallon, at St. Louis.[200] It appears that there are no minerals in this country, and, {329} in the immediate vicinity of Fort Clarke, not even lime. On the other hand, the strata of black, bituminous coal appear in the hills for many hundred miles. This coal ignites easily, with a strong sulphureous smell, but it does not emit sufficient heat to serve as fuel or for the forge.[201] In many places it may be evidently seen that these strata have been on fire. The surrounding clay is frequently burnt red, and the shards are perfectly coloured, hard and sonorous, like our bricks and Dutch clinkers. About Fort Clarke they know nothing of such fires, but they have frequently occurred lower down the Missouri. The red clay, which we have so often spoken of, appears to have been elevated by the action of fire. On the banks, extremely light, porous, cellular, red brown scoriæ are everywhere found, which the people here call pumice stone, though they are totally different from the fossil usually so called, and of which extensive strata are found on the banks of the Rhine. Petrifactions of animals and plants are to be looked for only on the banks of the rivers, though they doubtless are as frequent in the chains of hills, where they are concealed by the greensward from the eye of the passing observer. I was told that, in the prairie, about twenty miles distant from Fort Clarke, there are places in the hills where the organic remains of the antediluvian world lie exposed on the surface, but that country can be visited only for short intervals of time, and that, too, attended with great danger, on account of the hostile Indians. Entire petrified trunks of trees, such as we had observed on the banks of the Missouri, are said to be there, and impressions of crabs, or similar crustacea, have been found. The Indians speak of a petrified man, at the distance of three or four days' journey, whose head is round, and lies detached from the body. The story about the head is, probably, incorrect, as they pretend to be able to discern the countenance; but the rest of the skeleton is said plainly and distinctly to be seen. These are, doubtless, the remains of some antediluvian animal. It is much to be regretted that it is impracticable to explore, without much risk, a country so abounding with remains of this nature.
The extensive prairies, and their hills, certainly produce a great variety of plants, of which a part only have been described. Bradbury collected many plants about the Mandan villages, which were described by Pursh;[202] and Nuttall's works likewise contain many;[203] but there is, undoubtedly, much remaining to be done, especially in the chain of the Black Hills. The country, about the Missouri, has its peculiar botanical characters. The tongues of land at the bends of the river are generally covered with wood; other parts of the banks more rarely so; the species of trees and shrubs which occur here have already been mentioned. There are no pines in the vicinity of Fort Clarke; but they are found higher up the river; nor are there any birch trees; indeed, I did not meet with one on the whole course of the Missouri. These do not grow, except on the tributaries of the Upper Missouri, for instance, Knife River. At the distance of three days' journey from the mouth, at the foot of the mountains which are improperly called La Côte Noire, though they join the Black Hills, of which they are a branch, the latter form {330} a very interesting chain, which runs nearly in a north-east direction from La Platte and the great northern bend of the Missouri. They lie about 100 miles to the east of the Rocky Mountains, and form the watershed between the Missouri, Mississippi, and Arkansas, several rivers having their sources in those mountains.[204] Many kinds of fossils, and numerous species of plants and animals, which do not occur on the Missouri, are found on those hills. The paper birch (Betula papyracea) grows there, of the bark of which the northern Indians make the large pirogues, which are described in various works on North America. This tree is often thicker than a man's body; the bark is stripped off in large sheets, by making two parallel transverse incisions above and below, and then a perpendicular incision; after which the bark is loosened by means of wooden wedges. It is dry, and comes off very easily. Within is the smooth watered skin used by the Indians for writing their characters upon, from which circumstance the tree has derived its botanical name. The Black Hills are said to be likewise interesting in a zoological point of view. Among other animals found there, are the panther (Felis concolor), several species of rodentia, squirrels, &c.
In the prairies on the Missouri, near Fort Clarke, the same species of cactus are found as near Fort Union; the grasses are not of so many species as might be supposed; Chondrosium oligostachyum (Nees), which grows to the height of ten or twelve feet, and Bryzophyrum spicatum, are, however, found there. As I had no opportunity of botanizing here in the summer time, my list of plants of this part of the country is very incomplete; but Bradbury and Nuttall were more fortunate. Many officinal plants grow here, but there are no physicians to direct the use of them.
In the forests about Fort Clarke, only a very small quantity of useful timber is found. The poplar burns quickly, and emits much heat, and the bark serves for the winter food of the horses. The animal kingdom has many interesting species, for those of the extensive western prairies are united with those of the cold regions of North America. The best accounts of the former are given by Say, whose early death is deeply to be deplored:[205] and for those of the more northern regions, Richardson's admirable Fauna Boreali-Americana is replete with interest and information. The buffalo herds do not appear in the immediate vicinity of Fort Clarke, except when the winter is very severe, because they are too much disturbed by the numerous Indians in the neighbourhood. The hunters of the fort are often obliged to ride twenty miles before they find them. In the cold snow-storms, so prevalent during the winter, these animals take refuge in the forests on the banks, when great numbers of them are killed, and it is often almost impossible to drive them out of the wood. Their bones and skulls, scattered all over the prairie, prove the immense destruction which is made of these harmless animals. The elk may be shot at about eighteen miles from Fort Clarke; but it does not approach nearer, because of the Indians, to whom the skins of the elk are of great value in the manufacture of their shoes. The white-tailed {331} deer (Cervus Virginianus), called by the French, le chevreuil, is found in the nearest woods, not a mile from the fort. The black-tailed or mule deer is not to be seen within twenty or thirty miles. The cabri, or antelope (Antilocapra Ord.), lives the whole year in the immediate vicinity, and in the summer, great numbers congregate together; but in the winter they go towards the mountains, where they find protection against the snow, and return in April, when large herds of them are seen to pass the Missouri. The annexed woodcut, designed by Mr. Bodmer from the life, gives a perfect and correct idea of this animal.[206]
The bighorn (Ovis montana), the grosse-corne of the French, is not found nearer than fifty miles from this part of the country. The Manitaries, who go to the Black Hills and other mountainous tracts to hunt, kill a hundred or more of these animals in a season. The grizzly bear approaches to within four miles of the fort, because the Indians, who do not like to hunt them, leave them undisturbed. They are, however, very fond of the flesh of the young bear; and the claws are much valued by them, for the manufacture of their necklaces. Of the genus canis, I met with five wild species in western North America. The changeable wolf (Canis variabilis), undoubtedly a distinct species, as Lewis and Clarke likewise affirm, is very common on the whole of the Upper Missouri. It is found to vary in colour from wolf grey to pure white. In winter these animals are nearly famished, and extremely lean. They closely follow the herds of buffaloes, and many sick, young, or weak animals become their easy prey; and when the hunters are abroad there is a rich harvest for the wolves. They even bite and devour each other, yet they did not meddle with the dead wolves which we left in the prairie; possibly they might not have been so {332} ravenously hungry just then. They distinguish the report of a gun so well, that they hasten to the spot almost immediately after the shot has been fired. The same is the case with the ravens; and the Indian hunters affirm that the wolves watch these birds, in order to ascertain the direction in which the prey is to be found: if a poor animal has only been wounded, they are on the alert, and instantly pursue it, and it inevitably becomes their prey. In cold winters they are often so bold that they come into the villages, and approach the people's dwellings.
Head of Antilocapra Ord.
Head of Canis latrans