Geology

Inyo Crater Lakes

Mono County, CA

Coordinate verified

Pair of mid-14th-century phreatic (steam-blast) explosion craters on Deer Mountain above Mammoth Lakes—~600 ft wide and 100–200 ft deep, each holding a small forest-ringed lake, formed when rising magma flashed groundwater to steam without extruding lava.

Field facts

RegionMono County, CA
Coordinates37.6887, -119.0057
UnitInyo National Forest (USFS)
OriginPhreatic craters ~1350 CE
HikeShort loop from trailhead
Elevation~8,200 ft

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