Sunday, November 6, 2011

Mount St. Helens: Ape Caves

We had the wonderful opportunity to visit the Ape Caves with a geologist in the lead.  We also stopped by the Trail of Two Forests and the Lahar Viewpoint.  It was a long, but good day.

On the way up to our meeting point, I saw this beautiful viewpoint overlooking Yale Lake and stopped to grab a picture.

We arrived at the Trail of Two Forests and waited for the rest of our party.  We had lunch and explored the area immediately around the picnic benches.  Then our guide said a few words about volcanoes, explaining the types of eruptions we'd be seeing, the kind of volcano St. Helens is, and a few other interesting facts.

We got to see samples of vesicular basalt (aka lava with air bubbles).

The exciting thing about this part of the trip were the tree casts.  A lava flow from long ago wrapped about the trees in the area and hardened.  The trees either burned up or eventually decayed leaving behind hollow areas in the hardened lava rock.  We got to explore one of them.

One tree cast had a ladder heading down into it.  From there, you could crawl long a horizontal cast to an exit approximately 50 feet away.  It's small (hands and knees crawling on not-so-smooth rock), dark (need head lamps), and wet down there.  I know because I went through it.  Some of the kids loved it, and a few brave adults went through as well.

This is what the inside of the tree cast looks like from the exit.

After exploring the area, we headed back to our cars and drive a few miles up to the Ape Caves.  The Ape Caves are long tunnels running roughly parallel to the surface that were formed by lava moving underground.  There are two sections: the larger but more difficult upper tube and the easier lower tube.  We walked the lower tube.  The caves are pitch black, and the floor is uneven.  Multiple sources of good light are required to explore the tubes.

I knew Sam would love the Ape Caves, but he really loved them.  He was asking me to form another trip through them before we were even out of them.  Mika even enjoyed them; she ended up helping a couple of the younger kids through most of the walk.  (They just love her.)

Don't be fooled by the light picture!  I had my camera set on night portrait mode, and it does a very good job taking photos in the dark on that mode (still many of the photos have blurring and ghosting from the slow shutter speed).  This was on of the smoother, easier to walk in parts.

Other parts were rocky like this section.

This part is called the railroad tracks.  The raised tracks go on like this for quiet a while.

The rock overhead is called "Meatball".  It was apparently a block of cooled lava that fell from the ceiling while lava was still flowing through the tube.  It was carried downstream until it got wedged in a narrow space.

And this is the end of the 3/4 mile tube.  The floor becomes sandy.  The floor and ceiling gradually slope together until it dead ends.  At this point, there's nothing to do but go back the way you came.

After the Ape Caves, we drove 9 miles to the Lahar Viewpoint.   I was surprised to find snow on the roads (but it wasn't too bad), and the kids were thrilled.

When around snow, one must make a snow ball, right?

And throw it at someone.

It was sunset as we were driving back down the mountain.  After 9 1/2 hours, we finally walked back through our front door.    The kids loved it and want to go back. 

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Laser Kitty Artist said...

This is really cool! I am 11 years old and i found this website by looking up one of my rocks that I found 4 years ago. I think i may have the same molten lava rock as you guys but it is much lighter. It does have those bubbles in it though. It is pretty light weight and maybe you may be able to know what it is. Please reply if you do know.