Mount Humphreys is an 11,019-foot peak on Yellowstone National Park’s eastern boundary with the Washakie Wilderness in Wyoming and the sixth-highest mountain in the park. Part of the Absaroka Range, it rises steeply near Yellowstone Lake, with more than 2,600 feet of relief above Eagle Creek in a mile, and drains toward both the Yellowstone and Shoshone river systems. Its rugged slopes are part of volcanic terrain formed in the early Eocene, when volcanoes built much of this area. Named in 1871 by Captain J. W. Barlow for General Andrew A. Humphreys, the name was officially adopted in 1930.