[267] Notwithstanding this representation, and the fact that the peak in question was seen by ourselves at the distance of one hundred and thirty miles, we are inclined to the opinion, that in point of elevation, it falls far below many portions of the interior ridges of the mountains which are visible from its summit, and from the plains of the Platte, and that it is by standing a little detached from the principal group of the mountains, it acquires a great portion of the imposing grandeur of its appearance.

In the forenoon of this day we passed some tracts of grey sandstone; having, however, met with several inconsiderable conic hills belonging to that interesting formation, called by the disciples of Werner,[49] the fletz trap rocks. We perceived before us a striking change in aspect and conformation of the surface. Instead of the wearisome uniformity, the low and pointless ridges which mark the long tract of horizontal sandstone we had passed, we had now the prospect of a country varied by numerous continued ranges of lofty hills, interspersed with insulated cone-like piles, and irregular masses of every variety of magnitude and position. This scenery is not to be compared in point of grandeur with the naked and towering majesty of the great chain of the Andes, which we had lately left, but in its kind it is of uncommon beauty. The hills, though often abrupt and high, are sometimes smooth and grassy to their summits, having a surface, unbroken by a single rock or tree, large enough to be seen at the distance of a mile.

At noon we halted near the base of a hill of this description. It is of green stone, and the sandrock on which it rests is disclosed at the bottom of a ravine which commences near the foot of the hill. This latter rock is of a slaty structure, and embraces narrow beds of bituminous clay slate, which contains pieces of charcoal, or the carbonised remains of vegetables, in every possible respect resembling the charcoal [268] produced by the process of combustion in the open air. In the ravines and over the surface of the soil we observed masses of a light porous reddish-brown substance, greatly resembling that which is so often seen floating down the Missouri, and has by some been considered a product of pseudo-volcanic fires, said to exist on the upper branches of that river.[50] We also saw some porphyritic masses with a basis of greenstone, containing crystals of felspar.

In the afternoon several magpies, shore larks, and cow buntings were seen. One of the cow buntings followed us five or six miles, alighting on the ground, near the foremost of our line, and within a few paces of our horses' feet, where he stood gazing at the horses until all had passed him, when he again flew forward to the front, repeating the same movement many times in succession.

We had now arrived near that part of the country, where, according to the information of the Kaskaia, we expected to find the remarkable saline spring from which we were told the Indians often procured large masses of salt. The Kaskaia had, by the aid of a map traced in the sand, given us a minute account of the situation of the spring and of the surrounding country, stating that the salt existed in masses at the bottom of a basin-like cavity, which contained about four and a half feet of reddish water. Thus far we had not found a single feature of the country to correspond in the slightest degree to his descriptions, and as we had been careful to follow the general direction of the course he pointed out to us, it was probably his intention to deceive.

Our course, which was a little east of south, led us across several extensive valleys, having a thin dark coloured soil, closely covered with grasses, and strewed with fragments of greenstone. Descending towards evening into a broad and deep valley, we [269] found ourselves again immured between walls of grey sandstone, similar in elevation and all other particulars to those which limit the valley of Purgatory Creek. It was not until considerable search had been made, that we discovered a place where it was possible to effect the descent, which was at length accomplished, not without danger to the life and limbs of ourselves and horses. The area of the valley was covered with a sandy soil. Here we again saw the great cylindric cactus, the cucumis, and other plants common to the sandy districts, but rarely found in the scanty soils of the fletz trap formation. Pursuing our way along this valley, we arrived towards evening at an inconsiderable stream[51] of transparent and nearly pure water, descending along a narrow channel paved with black and shapeless masses of amygdaloidal and imperfectly porphyritic greenstone. This was the first stream we had for a long time seen traversing rocks of the secondary formation, whose waters were free of an impregnation of muriate of soda and other salts. From the very considerable magnitude of the valley, and the quantity of water in the creek, it is reasonable to infer that its sources were distant at least twenty miles to the west, and the purity and transparency of its waters afford sufficient evidence that it flows principally from a surface of trap rocks.

Having crossed the creek with some difficulty, we halted on its bank to set up our tent, and prepare ourselves for a thunder shower, which was already commencing. After the rain, the sky became clear, and the sun, which was near setting, gilded with its radiance the dripping foliage of a cluster of oaks and poplars, which stood near our tent. The grassy plain, acquiring an unwonted verdure from the shower, and gemmed with the reflection of innumerable pendant rain-drops, disclosed here and there a conic pile, or a solitary fragment of black and porous amygdaloid. The thinly-wooded banks of the creek [270] resounded to the loud notes of the robin, and the more varied and melodious song of the mocking-bird; the stern features of nature, which we had long contemplated with a feeling almost of terror, seemed to relax into a momentary smile to cheer us on our toilsome journey.

On the morning of the 29th, our course (S. 35° E.) brought us at the distance of three miles from our camp, to the foot of the cliff which separates the valley from the high plain. This mural barrier has an elevation of about two hundred feet, and is impassable, except at particular points, where it is broken by ravines. One of these we were fortunate in finding, without being compelled to deviate greatly from our course, and climbing its rugged declivity, we emerged upon the broad expanse of the high plain. Turning with a sort of involuntary motion towards the west, we again caught a view of the distant summits of the Andes appearing on the verge of our horizon. The scene before us was beautifully varied with smooth valleys, high conic hills, and irregular knobs, scattered in every direction as far as the eye could comprehend. Among these singular eminences nothing could be perceived like a continuous unbroken range. Most of them stand entirely isolated; others in groups and ranges, but all are distinct hills, with unconnected bases. The surface of the country generally, and more especially in the immediate vicinity of these hills, is strewed with fragments of compact or porphyritic greenstone. These are, in some places, accumulated in such quantities as render the passing extremely difficult.

At half-past eleven, A. M., a violent storm, with high and cold wind, came on from the north-east, and continued for two hours. Soon after its commencement we halted to dine, but were unable to find a spot affording wood until so much rain had fallen as to wet our clothing and baggage. Fire was almost the only comfort we could now command, our [271] provisions being so nearly exhausted, that about an ounce of jerked bison meat was all that could be allowed each man for his dinner.

The rain ceasing, we again resumed our journey, but had not proceeded far when we were overtaken by a second storm from the north-east, still more violent than the first, and attended with such pelting hail that our horses refused to proceed in any direction except that of the wind, so that rather than suffer ourselves to be carried off our course, we were compelled to halt, and sit patiently upon our horses; opposing our backs to the storm, we waited for its violence to abate. As soon as the hail ceased we moved on, the water pouring in streams from our mockasins and every part of our dress. The rain continued until dark, when, being unable to find wood, and having no occasion for water, we halted, and without the delay of cooking supper, or eating it, we set up our tent, and piled ourselves together under it in the most social manner possible. During the day the mercury had fallen from 70° to 47°, indicating a change of temperature, which was the more severely felt, as we were hungry, wet, and much fatigued. As we had neither dry clothing or blankets, we could find no other method of restoring the warmth to our benumbed bodies than by placing them together in the least possible compass. We spent a cheerless night, in the course of which Mr. Peale experienced an alarming attack of a spasmodic affection of the stomach, induced probably by cold and inanition. He was somewhat relieved by the free use of opium and whiskey.