Page:Early western travels, 1748-1846 (1907 Volume 6).djvu/164

 *lation would be curious. The marks of this loss, are very evident in the neighborhood of nearly all the rivers which discharge themselves into the Missouri above the Platte. Some of the appearances may rank amongst the greatest natural curiosities in the world. The traveller on entering a plain, is deceived at the first glance by what appears to be the ruins of some great city; rows of houses for several miles in length, and regular streets. At the first view there appears to be all the precision of design, with the usual deviations representing palaces, temples, &c.; which appearances are caused by the washing away of the hills, as before described. These remains, being composed of more durable substance continue undecayed, while the rest is carried off. The strata have the appearance of different stories; the isolated and detached hills constitute the remainder. I had this description from hunters, and from persons of intelligence who have met with them, and I have myself seen places near the Missouri very similar.

There is but a small portion of this extensive region that is not calcarious; in this respect resembling the section of the valley which {232} lies east of the Mississippi. A fact which is singular enough, on the summits of many of the river hills, about one thousand miles up, large blocks of granite are found, of several tons weight; these continue to be seen until we reach the first range of primitive mountains. It is possible there may have been a lower range, which from the change produced by the wearing away of the earth has gradually disappeared.

Some of the peculiarities of climate may be noted in this place. The height of this western region, and the open plains which compose it, cause it to possess a pure elastic air. The sky has a more delightful blue than I ever saw any where else; the atmosphere in a serene calm evening is so clear, that a slight smoke can be discerned