15th November, 1806: Saturday. Marched early. Passed two deep creeks and many high points of the rocks; also, large herds of buffalo. At two o'clock in the afternoon I thought I could distinguish a mountain to our right, which appeared like a small blue cloud; viewed it with the spy glass, and was still more confirmed in my conjecture, yet only communicated it to doctor Robinson, who was in front with me, but in halt an hour, they appeared in full view before us. When our small party arrived on the hill they with one accord gave three cheers to the Mexican mountains. Their appearance can easily be imagined by those who have crossed the Alleghany; but their sides were whiter as if covered with snow, or a white stone. Those were a spur of the grand western chain of mountains, which divide the waters of the Pacific from those of the Atlantic oceans, and it divided the waters which empty into the bay of the Holy Spirit, from those of the Mississippi; as the Alleghany does, those which discharge themselves into the latter river and the Atlantic. They appear to present a natural boundary between the province of Louisiana arid New Mexico and would be a defined and natural boundary. Before evening we discovered a fork on the south side bearing S. 25° W. and as the Spanish troops appear to have borne up it, we encamped on its banks, about one mile from its confluence, that we might make further discoveries on the morrow. Killed three buffalo.

27th November, 1806: Thursday. Arose hungry, dry, and extremely sore, from the inequality of the rocks, on which we had lain all night, but were amply compensated for toil by the sublimity of the prospects below. The unbounded prairie was overhung with clouds, which appeared like the ocean in a storm; wave piled on wave and foaming, whilst the sky was perfectly clear where we were. Commenced our march up the mountain, and in about one hour arrived at the summit of this chain: here we found the snow middle deep; no sign of beast or bird inhabiting this region. The thermometer which stood at 9° above 0 at the foot of the mountain, here fell to 4° below 0. The summit of the Grand Peak, which was entirely bare of vegetation and covered with snow, now appeared at the distance of 15 or 16 miles from us, and as high again as what we had ascended, and would have taken a whole day's march to have arrived at its base, when I believed no human being could have ascended to its pinical. This with the condition of my soldiers who had only light overalls on, and no stockings, and every way ill provided to endure the inclemency of the region; the bad prospect of killing any thing to subsist on, with the further detention of two or three days, which it must occasion, determined us to return.

Proceeding westwardly across the meridian above specified (ninety-fifth), the hilly country gradually subsides, giving place to a region of vast extent, spreading towards the north and south, and presenting an undulating surface, with nothing to limit the view or variegate the prospect, but here and there a hill, knob, or insulated tract of tableland. At length the Rocky Mountains break upon the view, towering abruptly from the plains, and mingling their snow-capped summits with the clouds.

On approaching the mountains, no other change is observable in the general aspect of the country, except that the isolated knobs and tablelands above alluded to become more frequent and more distinctly marked, the bluffs by which the vallies of watercourses are bounded present a greater abundance of rocks, stones lie in greater profusion upon the surface, and the soil becomes more sandy and sterile. If, to the characteristics above intimated, we add that of an almost complete destitution of woodland (for not more than one thousandth part of the section can be said to possess a timber-growth) we shall have a pretty correct idea of the general aspect of the whole country.