Try the short drive to the southern flanks of Mount St. Helens.

It will bring you face to face with a unique geology lesson below the Cascade Mountains, if you bring a flashlight or a lantern.

On the south side of the monument, you can explore Ape Cave, a lava tube that was formed centuries ago when lava poured from the volcano. When the lava finally stopped flowing, it left a two-mile-long cave that is the longest continuous lava tube in North America.

At the U.S. Forest Service Ape Cave Headquarters (open from late May through early September), you can join a ranger-led exploration of the cave or rent a lantern for exploring the cave on your own.

I recently met an energetic and fascinating U.S. Forest Service ranger (a recent transplant from East Asia) by the name of Neemedass (pronounced neem-ah-dazz ) Chandool (pronounced shan-doool ).

The young man was so well versed on the geology of caves and was so enthusiastic about sharing his knowledge that I learned more in two hours from his guided tour than from a semester in a college classroom.

I want to invite you to come with me on this walk back through time, said Neemedass, as our small group gathered near the entrance. And for those who ve never been here, remember that it s always about forty-two degrees, so you want to bring something warm to put on down below. Follow me!

And we were off--down deep into the ground.

The main entrance to Ape Cave is a sinkhole with two sets of stairs.

The first leads into the sinkhole, where a passage leads you several yards to the second stairway.

You feel the change as you descend into the cave: the warm comfort of July and the accompanying sounds of many visitors replaced by an abrupt stillness that takes a few moments to get used to.

Neemedass noticed our silence and said that it s not unusual for some people to be a bit uncomfortable as they warm up to the quiet coolness.

This tube was formed by an eruption that occurred almost two thousand years ago as the lava oozed and flowed from St. Helens. In some places the overhead roof is as much as sixty feet thick, he told us as we huddled around him in the dark.

In fact, the inky darkness was so eerie that my flashlight left something to be desired in the oppressive blackness.

Like many in my group, I was eager to move forward and learn more.

I learned that there are actually two caves in Ape Cave and that both begin in the middle of the lava tube near the interpretive center.

The upper cave is 1.5 miles long and requires some scrambling skills, but there is an exit from the upper level with a 1.5-mile trail back to the parking lot.

The lower cave is a much easier three-quarter-mile walk to the end of the cave, which shrinks down to a crawl way filled with sand.

You hike out by the same route. While our group stayed in the lower cave, more experienced spelunkers can hike either cave.

The evidence of long-ago molten activity cannot be missed, he continued as we journeyed deeper into the dark. Look around you! We are now in what s called Big Room, the largest open area of Ape Cave. Big Room has distinct flow markings on the walls that seem to have dripped and were then glazed over--almost like they were frozen in time.

There is a lot of moisture in the cave. At times, there are pools of water and mud on the floor, and the ceiling drips with cold water.

I quickly realized my heavy hiking boots, long wool pants, and warm jacket were exactly what s needed for this kind of adventure.

I also realized a willing spirit is needed to fully enjoy hiking in Ape Cave, so some may choose to stay above ground.

Yet I discovered a certain comfort and enjoyment in so much darkness and quiet. In fact, at times Ape Cave was so still the quiet seemed to shout at me. It was a thrilling experience, and I will return.

Be advised:

Each person will need warm clothing and a good flashlight.

During the summer you can rent lanterns at the interpretive center for a small fee.

No food, pets, or firearms are allowed in the caves.

Running or hiking shoes are adequate for the lower cave, but some of the lava formations are sharp enough to shred them; open-toed sandals are definitely not a good idea.

You ll need to purchase a Northwest Forest Pass at any of the monument visitor centers or at Pine Creek on the south side of the mountain.

Getting There:

Ape Cave: Take Interstate 5 to Woodland (exit 21) and head east on Washington 503 to Yale. At Yale, turn left on Forest Service Road 90 to Cougar. At 7.5 miles east of Cougar, turn left (north) on Forest Service Road 83. In less than two miles, turn left (west) on Forest Service Road 8303 to the parking lot at Ape Cave Headquarters.

For More Information:

Mount St. Helens National Volcanic Monument Headquarters, 42218 N.E. Yale Bridge Road, Amboy, WA 98601, (360) 449-7800
Ape Cave Headquarters, (360) 247-3900

Read or Share this story: