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Ape Cave

Lava Tube in Mt. St. Helens National Volcanic Monument, Gifford Pinchot NF, Cascade Range near Cougar Park, WA

Sensitive Place

Lava Tubes are sensitive in nature and deserve the utmost respect. Please help preserve the area for future generations.

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Length

1.9mi

On the Web

On Wikipedia

Ape Cave is a lava tube located in Gifford Pinchot National Forest just to the south of Mount St. Helens in Washington state. Its passageway is the longest continuous lava tube in the continental United States and the third longest (in total mapped length) lava tube in North America at 2.5 miles (4,023 meters). Ape Cave is a popular hiking destination with beautiful views of the Mount St. Helens lahar region. Lava tubes are an unusual formation in this region, as volcanoes of the Cascade Range are mostly stratovolcanos and do not typically erupt with pahoehoe (fluid basalt). The cave was discovered circa 1951 by Lawrence Johnson, a logger, when he noticed a tree that "looked wrong." After investigating the tree, he discovered it tilted into a lava tube collapse. A few days later, Johnson…

Classified As

Lava Tube