Captain Clarence Dutton (1841-1912) began to work for Powell in 1875 and for the US Geological Survey from 1879-1891. From 1875-1877 he and his team mapped over 12,000 square miles along the Colorado and Green Rivers and their tributaries which included the areas that would later be designated as National Parks including Canyonlands, Bryce, Zion and the Grand Canyon.
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