Broken Top is a glacially eroded complex stratovolcano. It lies in the Cascade Volcanic Arc, part of the extensive Cascade Range in the U.S. state of Oregon. Located southeast of the Three Sisters peaks, the volcano, residing within the Three Sisters Wilderness, is 20 miles west of Bend, Oregon in Deschutes County. Eruptive activity stopped roughly 100,000 years ago, and erosion by glaciers has since reduced the volcano's cone to where its contents are exposed.