[trip] Pacific Northwest Lava Tubes

I recently took a two-week trip to the Pacific Northwest in order to see a part of the country that I've never yet visited. Of course I couldn't take a trip without doing a bit of caving, so I took the opportunity to check out my first lava tube caves.

In Oregon, located near the Newberry National Volcanic Monument in the Deschutes National Forest, I first visited Boyd Cave. This easily-accessed lava tube has a small entrance hole with a metal staircase leading down into over 1000 feet of easy, round passage between 10 and 20 feet tall. The cave is very dry, and small breakdown piles are found occasionally. The cave is worth seeing if you're in the area, but a bit too "bland" to warrant a trip to Bend just to visit it.


The entrance to Boyd Cave, from the inside looking up and out the small collapse entrance.

I then traveled a short distance up the road to try and visit Skeleton Cave, reported to be 3000 feet and more sporting. I arrived to find that the cave was gated and locked (supposedly for hibernating bats), despite it no longer being hibernation season. I checked out about 50 feet of low cave on the non-gated side, but could do nothing more than admire the impressive collapse sinkhole entrance of Skeleton. I had a very enjoyable night camping just outside the cave, under a full moon, in Oregon's high desert.


Large collapse sink entrance to Skeleton Cave. The bat gate is about 30 feet wide, and was locked in June.

In Washington, during a several day stay on Mt. St. Helens, I awoke early (for me) and headed into Ape Cave at 9am. Ape is probably the most-visited lava tube in the US, and its long, straight, flat and sand-floored passage makes it well-suited for this. I headed in the main entrance and went downhill, with the entire cave to myself. The hallway passages are frequently 25 feet wide and probably between 30 and 40 feet tall. It was certainly more impressive than was Boyd, but only barely.

Once to the pinch-out end, 3/4 mile from the entrance, I turned and headed back out where I met three schoolbus loads of middleschool kids going into the cave. Great. I hiked about a mile and a half to the upper entrance, stopping to check out lots of little lava bubbles and FROs (the lava equivalent of karst, I suppose) on the way, finally reaching the large collapse sinkhole at the upper entrance. Here I found a group of 8 seventh-graders with about 6 lights between the entire group, planning to head down and pop out the main entrance. Upper ape has a lot more breakdown and is a bit more sporting than lower ape. I gave them two of my spare lights and helped them navigate some of the climbs, we encountered dozens more schoolkids on the way out.


A small "lava FRO" near Ape Cave. I went in one entrance, explored about 15 feet of cave, and popped out the second entrance. The area is full of small lava bubbles like this.


Small "skylight" between the upper and lower entrances to Ape Cave, as seen from inside.

Finally, just a mile or so from Ape, I visited Lake Cave. Another beautiful basalt collapse sinkhole slopes down into stooping passage which opens to the top of a 30 - 40 feet tall lava canyon. The canyon is rigged with a ladder, which is chained and bolted to the wall. Lake was a great lava tube! The cave seems to flow down a steeper grade, occasionally with "lava falls", plenty of breakdown and climbing, and very spacious, tall lava canyon passage - probably 40 - 50 feet tall and 30 feet wide in some places. The lava walls appear to have been melted and re-melted, and dripped and flowed like molten chocolate ice cream in places. Lake Cave ends in a disappointing lava ash choke with an inches-deep pool of water - hardly a lake. This cave must have gone for over a mile, and was quite enjoyable. If you go to Mt. St. Helens, do Lake Cave instead of Ape Cave!


Scenic collapse entrance to Lake Cave. The landscape is mainly moss-covered basalt with very little topsoil.


Goopy, melted ice cream lava walls in Lake Cave. Photos can't do justice to the alien texture.

While I was impressed with the length and the passage dimensions in most of the lava tubes that I visited, the caving itself was a bit boring. Not much to see (no formations, of course), no real leads or anything beyond single-passage caves, little climbing or squeezing. However, the potential for undiscovered lava tubes of significant size is very great - they're only discovered when ceilings happen to collapse, so there's bound to be many many more to be found (or dug into). Project caving in the Pacific Northwest sounds like it could be very rewarding, but for now I'll stick to my WV stream caves!

All photos by David A. Riggs

See also: more of my lava tube photos