Global Volcanism Program | Image GVP-03301
In 1995 soil gas fluctuations caused tree dieback at Horseshoe Lake on the SE side of Mammoth Mountain. A period of unrest including uplift and seismic swarms has continued for more than a decade.
Photo by Dave Wieprecht, 1995 (U.S. Geological Survey).
This image is made available as a Public Domain Work, but proper attribution is appreciated.