 Washburn–Langford–Doane Expedition

The Washburn Expedition of 1870 explored the region of northwestern Wyoming that two years later became Yellowstone National Park.Led by Henry Washburn and Nathaniel P. Langford, and with a U.S. Army escort headed by Lt. Gustavus C. Doane, the expedition followed the general course of the Cook–Folsom–Peterson Expedition made the previous year.