Red Cones, two closely spaced basaltic cinder cones SW of Mammoth Mountain, near Devils Postpile National Monument, are youthful unglaciated cones that were erupted about 8900 years ago. The two breached cones fed lava flows that joined to form a flow 2 km long and 2 km wide. The southern cone is seen here from the flanks of the northern cone. The reddish oxidized scoria of both cones is mantled by light-colored pumice erupted from the Inyo Craters about 650 years ago, visible here at the base of the northern cone.

Photo by Lee Siebert, 1998 (Smithsonian Institution)

This image is made available under the Public Domain Dedication CC0 license, but proper attribution is appreciated.

Mammoth Mountain