Did you know you know that the continental United States’ longest lava tube lies just above Portland in the Gifford Pinchot National Forest? Mapped at 2.5 miles, this impressive tube was formed from a 2,000-year-old lava flow of Mount St. Helens, and was discovered in 1951. Since then, it has played host to over 170,000 visitors annually.

Even for the brave, entering a cave is a bold step. Exploring under the ground requires preparedness – mostly from the dark that lies beneath where no light can shine. A warm set of clothes is a must to protect you from the brisk 42 degree climate that greets you as you descend the staircase to enter the cave. Grab your flashlight (and a backup one as well), and head into the woods to explore this epic cave yourself.

Brian Brewer / Flickr
Stairs make the caves accessible year-round. The Lower Cave is .75 miles long and is the easier of the two caves, taking just about an hour to complete the hike.
Vineesh Divasia / Flickr
The Upper Cave is longer, at 1.5 miles, and is more strenuous. This hike will take over 2 hours to complete and requires some light climbing and maneuvering around large rocks in the path.
Abhinaba Basu / Flickr
The cave has 30-foot ceilings throughout much of its path. Formed by fluid basaltic lava, the caves represent the only known basaltic eruption of Mount St. Helens in its history. It is thought that lava flowed through the tubes for months or even a year as the volcano erupted, forming these tubes.
Whateverthing / Flickr
Today, thousands of people visit the site annually to explore this underworld beneath the surface.

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Abhinaba Basu / Flickr
Because the trails are easily maneuverable, children and adults are both able to hike the tunnels with ease.
Abhinaba Basu / Flickr
The name, Ape Cave, was coined after a group of Boy Scouts, who were sponsored by the St Helens Apes, a forestry group in the area, were the first to explore the cave.
iwona_kellie / Flickr
If you plan on visiting, be sure to wear plenty of layers and hiking shoes or boots, and bring a headlamp and flashlight. Because the caves are on federal land, a $5 fee is required for parking. December through March, a Washington State Sno-Park Permit is required.
The Jedi / Flickr
When you reach the light at the end of the tunnel, you know you have made it. Be sure to bring a camera to capture this amazing natural wonder for yourself.

Have you been to this cave near Portland?

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