Powell Geographic Expedition of 1869

The Powell Geographic Expedition of 1869, led by American naturalist John Wesley Powell, was the first thorough cartographic and scientific investigation of long segments of the Green and Colorado rivers in the southwestern United States, including the first recorded passage of white men through the entirety of the Grand Canyon.

Despite a series of hardships, including losses of boats and supplies, near-drownings, and the eventual departures of several crew members, the voyage produced the first detailed descriptions of much of the previously unexplored canyon country of the Colorado Plateau.

Knowing the altitude was essential for producing good maps, and it allowed Powell to estimate how much vertical drop remained before the journey's endpoint, which had a known elevation.

The Powell expedition named many of the landmarks and geological features along the Green and Colorado rivers, including the Flaming Gorge, the Gates of Lodore (in what is now Dinosaur National Monument), and Glen Canyon.

Frank Goodman left the expedition on July 6 during the resupply at the Uinta River Indian Agency, claiming he'd had more than enough adventure.

First camp of the second John Wesley Powell expedition, in the willows, Green River, Wyoming, 1871. There were no photographs taken on the 1869 expedition.