Along the picturesque Middle Fork of the San Joaquin River at
7,600 feet on the western slopes of the Sierra Nevada lies Devils Postpile
National Monument. This formation began when basalt lava erupted in the
Middle Fork valley. As lava flowed from the vent, it filled the valley near
the postpile to a depth of 400 feet. Surface cracks formed when tensions
caused by the shrinkage of the cooling lava were greater than the lava's
strength. Each crack branched when it reached a critical length. Ideal
conditions allowed surface cracks to deepen and form long post-like
columns.
Proclaimed July 6, 1911;
Acreage- 798.46, all federal
For more information:
c/o Sequoia and Kings Canyon National Parks
Three Rivers, CA 93271
209-565-3341
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