Exploration of the Colorado River of the West and Its Tributaries Explored in 1869, 1870, 1871, and 1872, Under the Direction of the Secretary of the Smithsonian Institution.

Page 166, Exploration of the Colorado River

166 EXPLORATION OF THE CANONS OF THE COLORADO. in the rocks through which the channels are now carved, but that the beds in which the streams had their origin when the district last appeared above the level of the sea, have been swept away. I propose to call such superimposed valleys. Thus the valleys under consideration, if classified on the basis of their relation to the rocks in which they originated, would be called consequent valley s, but if classified on the basis of their relation to the rocks in which they are now found, would be called superimposed valleys. Eecurring again to the valleys of the Uinta Mountains, it may be well to remark here that, coming from the Rocky Mountains to the study of the Uinta Mountains, I at first supposed that the valleys of this region also were superimposed upon the rocks now seen, but gradually, on a more thorough study, the hypothesis was found to be not only inadequate to the explanation of the facts, but to be entirely inconsistent with them; and again and again I visited the region, and re-examined the facts, and at last reached the conclusion which I have heretofore stated. A brief reference to the character of this evidence may not be out of place here, though I reserve the subject for a more full discussion in my report on the geology of the Uinta Mountains. If the valleys were superimposed on the present rocks, they must be consequent to rocks which have been carried away; but the valleys consequent upon the corrugation, which was one of the conditions of the origin of the Uinta Mountains, could not have taken the direction observed in this system; they would have all been cataclinal, as they ran down from the mountains, and turned into synclinal valleys at the foot, forming a very different system from that which now obtains. Again, the later sedimentary beds, both to the north and south, were found not to have been continuous over the mountain system, but to have been deposited in waters whose shores were limited by the lower reaches of the range; that is, they all gave evidence of littoral origin, and, further, that the principal canons through the mountains had been carved nearly to their present depth before the last of these sediments were deposited. BAD-LANDS AND ALCOVE LANDS SOUTH OF THE UINTA MOUNTAINS. South of the Uinta Mountains, and beyond the hog-backs on either side of the river, is a district known to the Indians as Wa-ka-ri'-cliits, or the