Lassen Peak
Lassen Peak, a volcanic mountain in the Cascade Range in northern California. The peak rises 10,466 feet (3,190 m) above sea level. It last erupted in 1914-15 and has occasionally emitted gases and steam since. Lassen Peak is the chief feature of Lassen Volcanic National Park, which includes cinder cones, lava beds, hot springs, and boiling mud pools.