The Ape Cave lava tube is a rare geologic site near Mt. St. Helens, Washington., where you can hike inside an ancient, cooled lava flow.
This incredible experience brings thousands of tourists to the cave every year.
But did you know that the cave was discovered by a boy scout troop? Or that it’s named indirectly after Bigfoot? Or that the walls are coated in a special fungus called “cave slime”?
In this article, we’ll look at some of the coolest facts about an interesting destination: The Ape Cave lava tube in Washington.
1. Ape Cave was Created by a Lava Flow from Mt. St. Helens
Lava tubes are relics of volcanic eruptions.
When volcanoes erupt, they release hot magma – not just from the active crater of the volcano, but also in channels below the ground called “pyroducts”.
While the volcano is still erupting, these channels are filled with superheated magma. However, as the eruption subsides, the tunnel narrows and then settles, leaving behind an empty passage through the earth lined with volcanic basalt.
Although it takes up to a year for a lava tube to cool completely. Once it does, it becomes a habitat for all kinds of animals that prefer the darkness.
Although Mt. St. Helens erupted as recently as 1980, the Ape Cave lava tube is a result of a much earlier eruption, about 1900 years ago.
2. Ape Cave is the Longest Lava Tube in North America.
There are lava tubes around the world, especially around active volcanoes.
Some of the most remarkable lava tubes are in Hawaii, where they are comparatively young, having formed 500 years ago or less. The Kazamura lava tube system in Kileua is 40 miles long!
However, Ape Cave is the longest and most impressive lava tube in all of North America.
At 2.5 miles long, it is an extensive cave hike with high ceilings and a volcanic basalt environment.
3. Boy Scouts Were The First To Explore It
Ape Cave was first discovered in 1947 by a logger named Lawrence Johnson, who almost drove his tractor right into it.
However, it wasn’t explored until several years later, when Johnson mentioned the cave system to a friend of his who was a leader of a local boy scout troop.
Harry Reese organized the first expedition into the caves by lowering the boy scouts 17 feet down into the caves, where they did an initial exploration.
4. The “Ape Cave Lava Tube” is Named After Bigfoot
Well, not really.
The name “Ape Cave” came from the boy scout troop who first explored it, after their sponsors, a local group of loggers who called themselves the St. Helens Apes.
At the time, logging was a major part of the local economy and it was common to call foresters “apes” or “brush apes”, referring to the legend of Bigfoot.
So although technically the caves are named after a local group of loggers, you can still trace the term back to Bigfoot.
4. It’s Cold in the Caves
Although the temperature on the surface can vary widely during the year, depending on the season, the temperature inside the caves stays around 40 F – which is pretty cold.
The hike to the caves might be warm, but you’ll want to bring a sweater or a jacket into the caves, where the warmth of the sun never reaches.
5. It’s Dark Enough That You Can Get Very Disoriented.
One of the highlights of hiking the Ape Cave lava tube is turning off your headlamp.
Hiking through a cave is dark, but most people aren’t aware of just how dark it can get.
Without any source of sunlight, it is perfectly pitch black inside the caves, and when you don’t have any source of light it can cause an interesting kind of disorientation, in which you’re not sure which way is up or down, left or right.
You can’t see your own body, including your hands, when they are right in front of your face!
It’s dangerous to be without a light source, which is why hikers are recommended to bring 2 or 3 different lamps, but you would miss out if you didn’t take the opportunity to experience the complete darkness of a lava tube.
6. The Walls of the Cave are Covered in “Cave Slime.”
Don’t touch the walls of the cave.
There is a white moisture that covers the walls in the Ape Cave lava tubes called “cave slime”.
It’s actually a very fragile variety of fungus that takes years to grow and serves as the basis of the food chain in the deep cave environment.
It is tremendously important to all of the creatures that live in the cave, but it dies when touched.
Unfortunately, some people who don’t know better have smudged, smeared, and even written their names or messages in the cave slime.
Subterranean hiking trails are much more ecologically vulnerable than trails that run through a forest on the earth’s surface.
It’s good practice to leave nothing behind wherever you hike, but it’s especially important to preserve the environment and the delicate ecosystem in the Ape Cave lava tubes.
7. There Are 2 Different Hikes
There are upper and lower portions of the Ape Cave lava tube, in addition to a hike along the trail from the trailhead to the entrance to the cave.
The lower cave is easier. It extends about 3/4 of a mile and is 1 way. It’s a perfect hike for novices and families.
The upper portion of the cave is longer and more challenging. It extends 1.5 miles and culminates in climbing up an 8-foot rock wall and scrambling over piles of rocks to get back to the surface.
This route requires a little more dexterity, but it is still pretty accessible to average hikers.
Either way, you’ll need to bring warm clothes, sturdy footwear, at least 2 sources of light that are stronger than a cell phone, and enough water to sustain you through the hike.
Hiking the Ape Cave Lava Tube
The hike takes most people only a couple of hours, but the memories will last much longer.
It’s difficult to describe how interesting and vast the lava tube is on the inside, with ceilings as high as 50 feet above you in places.
There are interesting geologic formations everywhere, including “the meatball” – a place where a sphere of rock basalt formed and flowed through liquid magma into a narrow crevice where it got caught.
If you have the opportunity to experience this cave hike, take full advantage of it by arriving prepared for a challenging hike, and leaving no trace behind so that this amazing natural wonder is preserved for future generations.
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