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Show EEOSIOK 15 improbability, though the proofs are difficult beyond a certain amount. The great value of the Plateau Country is the certainty and fullness of the evidence. Nature here is more easily read than elsewhere. She seems at times amid those solitudes to have lifted from her countenance the veil of mystery which she habitually wears among the haunts of men. Elsewhere an enormous complexity renders the process difficult to study; here it is analyzed for us. The different factors are presented to us in such a way that we may pick out one in one place, another in another place, and study the effect of a single variable, while the other factors remain constant. The land is stripped of its normal clothing; its cliffs and canons have dissected it and laid open its tissues and framework, and "he who runs may read" if his eyes have been duly opened. As Dr. Newberry most forcibly remarks: "Though valueless to the agriculturist, dreaded and shunned by the emigrant, the miner, and even the adventurous trapper, the Colorado Plateau is to the geologist a paradise. Nowhere on the earth's surface, so far as we know, are the secrets of its structure so fully revealed as here." In the new era, beginning with the desiccation of the lake, we have the history of a process which resulted in the destruction and dissipation of those great bodies of sediment which had been gathered and stratified during Mesozoic and Eocene time. Then, too, appears to have begun in earnest the gradual elevation of the entire region which has proceeded from that epoch until the present time, and which even yet may not have culminated. The two processes of uplifting and erosion are here inseparably connected, so much so, that we cannot comprehend the one without keeping constantly in view the other. From the very inception of the process the drainage system of the Plateau Province has been that plexus of streams which unite in the Colorado River. This is the trough through which the waste of the land has been carried to the Pacific. Its origin goes back to the emergence of the land now drained by it from its lacustrine condition. Even prior to that we may conjecture the existence of a Cretaceous-Eocene strait connecting with the ocean that area which was covered by the Laramie beds and the brackish water deposits at the base of the local Eocene; and many considerations lead to the inference that this Hellespont occupied the same position |