Large volcanoes serve as a backdrop to the city of Bend in Deschutes County, ranging from the prominent Three Sisters, Mt. Washington, Mt. Bachelor, Broken Top, Newberry, Tumalo Mountain, Maiden Peak and others. A group of geologists have discovered Smith Rock State Park is part of an ancient supervolcano called the Crooked River caldera with a rim nearly six times the diameter of Newberry Volcano's caldera. This ancient supervolcano has long gone extinct. Its crater rim is barely recognizable as remnants mark portions of Powell Buttes, Gray Butte, and the western front of the Ochoco Mountains at Barnes Butte.