Four Craters Lava Field

Four Craters Lava Field in Oregon, southeast of Newberry Caldera, is a broad basaltic lava field rather than a single mountain, covering about 30 square kilometers. It formed after the eruption of Mount Mazama and was fed by four Holocene cinder cones aligned along a northwest-trending fissure. The cones rise above the surrounding lava flows, making the field’s volcanic structure visible in the landscape. At its southwest corner, Crack-in-the-Ground marks the western edge of a shallow volcano-tectonic depression created as older rock subsided during eruptions. Together, the lava field and fracture show how volcanism and crustal movement shaped the same terrain.

Oregon · United States