John Wesley Powell's work as an explorer, a geologist, and an anthropologist in the American West helped to shape national policies regarding the development of public lands and the welfare of Native American tribes. Celebrated in 1869 for leading the first American expedition through the Grand Canyon of the Colorado River, Powell's greater contribution came in the form of scientific reports-many of which went against long-held beliefs-on western lands and the peoples living there. Powell's advocacy of communal or government control of water for irrigation in the West was derided at the time, yet his studies served as the foundation for twentieth-century water-use policies. As director of both the U.S. Geological Survey and the Bureau of Ethnology, he saw science as a vital force in promoting the common good. These photographs show Powell and two different Paiute men during his 1873 expedition into the Southwest.