Among the enisled high plateaux of Eastern Utah the brilliant isostasy theory had its birth. When these arid mountains first became the subject of special description, about 1880, no such thing as a distinctive desert geology was entertained. Possibility of a definite geographic cycle in land sculpture was one of the modern earth conceptions yet undreamed. Competency of the wind as a general erosive agency was not yet established. Operation of epeirogenic movements was little understood. Omission of such basic considerations necessarily led to curious aberration in interpretation of the phenomena presented by lands of little rain.