Mono Basin and Hot Creek Area

Crowley Lake and the White Mountains east of Hwy 395. Long Valley is a huge caldera caused by the collapse of a monster-size volcano over 500,000 years ago. The collapse was preceeded by a large erruption of 35cubic miles of super-heated magma over an area of 450 square miles. This resulted in the formation of extensive table lands east of today's Sierra Nevada.