By 1869, four separate surveys were being conducted in the American West by an eclectic selection of leaders. Clarence King, commissioned to map around the 40th parallel, was a civilian geologist, while George Wheeler was an army engineer. Also active were John Wesley Powell, an autodidact Professor of Geology, and Ferdinand V. Hayden, a physician by training. Wheeler began with a limited brief, surveying the head of navigation of the Colorado River; in 1872 he requested, and had approved, an ambitious commission to map all of the United States west of the 100th parallel. Wheeler would complete the mapping of most of the American Southwest before the work of the pioneers was subsumed within the newly founded United States Geological Survey in 1879. King completed his geological survey in 1873, producing maps of high quality with copious data of value to the mining industry; he also attained celebrity by exposing an elaborate diamond hoax in Colorado.
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