John Wesley Powell: Conquest of the Canyon By (author): "Vada F. Carlson"Genres:Childrens books Biography books Words books The 1700s books ISBN0817851313ISBN139780817851316AsinJohn Wesley Powell: Conquest of the CanyonOriginal titleJohn Wesley Powell: Conquest of the canyonA biography of the geologist who led the first expedition down the canyons of the Green and Colorado rivers in 1869.