Gearhart Mountain is an 8,364-foot peak in south-central Oregon, rising within the Gearhart Mountain Wilderness of the Fremont–Winema National Forest near the boundary of Lake and Klamath counties, northeast of the Sprague River valley and Bly. Geologically, it is one of Lake County’s larger volcanoes. It formed as both a Miocene shield volcano and stratovolcano, then was gradually reshaped by erosion and became extinct. Its significance lies in this combination of volcanic origin and present character as a high, rugged summit in a protected wilderness setting rather than an active volcanic landmark.