Butte Lake in NE Lassen Volcanic National Park was formed when the blocky lava flow seen across the lake dammed local drainages. The flow was one of five accompanying the eruption that formed Cinder Cone several hundred years ago. This marks the NW-most extent of lava flows from Cinder 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.

Lassen Volcanic Center