Geologic Trip,

Mammoth Area

Mammoth Mountain


Mammoth Mountain is a volcano that lies along the southwestern rim of the Long Valley Caldera. The volcano began to take shape 200,000 years ago and was built up over the next 160,000 years by a series of a dozen or so eruptions of rhyolite and andesite interspersed with layers of tuff, scoria, and pumice. The last of these eruptions was about 40,000 years ago. The volcano is still active and new eruptions could occur some time in the future.

Related Links

Geologic background: Mammoth Area (pdf)

Geologic trips: Devils Postpile Hot Creek Gorge Mammoth Mountain Owens Gorge


Exterior Websites

USGS: Field Guide, Mammoth Mountain, Long Valley Area Map