John Wesley Powell was drawn to the river throughout his life, and at an early age he often made long trips alone in his boat on the Mississippi and Ohio Rivers. He lost an arm at the battle of Shiloh during the Civil War, but this did little to impede his vigorous travels on America’s western rivers. Powell conducted pioneering surveys on the Green and Colorado rivers, and he survived a hazardous passage by boat through the Grand Canyon in 1869 and again in 1871.

Powell’s classic 1875 Exploration of the Colorado River of the West and Its Tributaries vividly describes the Colorado River’s natural features and points out that the formation of canyons is due to the corrosive action of rivers. From 1871 to 1879 Powell surveyed western lands in the public domain and later served as director of the U.S. Geological Survey, mapping water resources. Powell’s proposals for laws protecting the arid deserts of the west are recognized as masterpieces of government. His views on America’s use of its natural resources have influenced conservationists through today.