Coso volcanic field lies in inyo county california at the western edge of the basin and salton buttes. Very high threat potential 1 lassen volcanic center long valley caldera mount shasta high threat potential 1 clear lake volcanic field medicine lake mono inyo chain salton buttes moderate threat potential 1 coso volcanic field mammoth mountain mono lake volcanic field soda lakes nv ubehebe craters 1. Red hill one of the four salton buttes small volcanoes on the southern san andreas fault at the salton sea is seen on june 30 near calipatria california. Helens it is the only volcano in the contiguous us that erupted in the 20th century. Lassen s summit complex is a lava dome that rises 2 000 feet 610.
It is the highest volcano in california with an elevation of 14 179 ft. The stratovolcano last erupted in 1786 is believed to have been observed by french explorer lapérouse. Coso volcanic field lies in inyo county california at the western edge of the basin and salton buttes.
