| Timothy H. O'Sullivan 15. the "Vermillion Cliff," a typical plateau edge, as seen from Jacobs Pool, Arizona. From its top, a plateau stretches to the right, and from its base another to the left. Their difference of level is 1,500 feet, and the step is too steep for scaling. [Wheeler Survey, Explorations and Surveys West of the 100th Meridian] 1871-1874 (survey), 1872 (expedition) Stereocard Etherton Gallery LL/24738
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