Olallie Butte is a steep-sided shield volcano in the Cascade Range of northern Oregon. It is the largest volcano and highest point in the distance between Mount Hood and Mount Jefferson, Oregon's two highest peaks. Ice Ageglaciers carved two large cirques into the northeast and southeast flanks of the mountain exposing magma which hardened in the volcano's conduits to form the numerous spectacular pinnacles now found in the higher parts of the cirques.