Lava Land #2: The Big Obsidian Flow, AKA The Glass Mountain

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August 16th 2010
Published: August 16th 2010
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August 12-13, 2010: Having found out that there's a bigger crater in Oregon than Crater Lake (crater = caldera: the basin resulting from a violent volcanic eruption) we of course had to see it.
A part of Newberry National Volcanic Monument, this crater is 26 miles across! But more recent events in geologic time have built a partition across the caldera, so where Crater Lake is one lake, at Newberry there are two: Paulina Lake and East Lake.
Heading south from Lava Butte and then turning east, up, up, up we drove. Paulina Lake is the first one reached, at 6,300 or so ft (more than a mile above sea level, for those of you who have forgotten some of the math). Again worried we might not find a place, we grabbed a campsite there. As this was the same day we'd “done” Lava Butte, we rested once we made camp—you know, a snack, a cup of tea, later a glass or two of red and, that camper's delight, tinned beans. We'd been carrying them a long way, so this was the night.
In the morning we headed for the “Big Obsidian Flow”, not knowing quite what to
Stairway to glass heavenStairway to glass heavenStairway to glass heaven

Don't bring your dogs! They'll cut their paws.
expect. And who would? (OK, Kitty, you would.) Well, it was literally a mountain of black glass! Obsidian (glass) forms when lava is high in silica and low in gaseous content and it cools quickly, so there isn't time for it to form crystals. I never thought of glass as disorganized, myself, it always seemed pretty clear and finite to me, but at its inner being, it is molecularly random. So there, even the best appearances can be deceiving.
Anyway, being made of glass, there were signs advising people to not bring their dogs up the path as their feet would get cut, and people should not wear flipflops, either (ie thongs to you Ozzies—different meaning entirely here.) As we stepped along the path there was that tinkling sound of glass windchimes from our footfalls—seemed pretty amazing.
When we got to the top, we could see Paulina Lake, where our campsite was, and beyond again to Sisters and Bachelor Mt. as well as the geologic partition between the lakes, but we couldn't quite see East Lake. Here and there life forms struggled to survive on dust and puddles. I always find this a metaphorical sight. And inspiring.
Wall of glassWall of glassWall of glass

This huge pile was the "foothills" of the glass mountain
And it seemed some people had intervened a bit with the landscape by placing chunks of obsidian on top of boulders in strange ways. “Better than writing their names,” opined Phil.
Now Kitty, Phil has a question he hopes you can answer: Why are there pale grey stripes in the obsidian???
Later that day we drove on to East Lake, and if I were to go again, that's the one I'd pick to stay at. I thought the sites were a little more private and there was a beach and swimming. It was a huge park, with over 100 campsites, well spaced out and many right on the water. But in either campground, forget about having a shower. There were a small number of flush toilets, but no showers anywhere that I could discover.
Paulina Lake is stocked with salmon and trout, it appears to be the fisherman's favorite, and I could well imagine Justin and Les out there on its blue blue deep waters. Paulina Lake also has an excellent walking path all around its circumference (7.5 mi) and the added benefit of a lodge with a shop that sells Ben and Jerry's ice cream on
Obsidian flow shoulderObsidian flow shoulderObsidian flow shoulder

The view from the top of the stairs
a stick. Hurray for Cherry Garcia.
And gracias to life for all these adventures.

Additional photos below
Photos: 19, Displayed: 19


Mountain of black glassMountain of black glass
Mountain of black glass

The Big Obsidian Flow is the most recent volcanic activity here--it happened 1300 years ago. This site was extremely valuable to Native Americans who traded the glass for making tools and weapons to tribes further west who had more food.
Ever the scientistEver the scientist
Ever the scientist

Phil makes comparison weighings of different pieces of obsidian and pumice
Little pine basing life on some dust in a puddleLittle pine basing life on some dust in a puddle
Little pine basing life on some dust in a puddle

Is there the making of a children's book in this picture?
Phil puzzles over...Phil puzzles over...
Phil puzzles over...

Please Kitty: Why are there thin grey stripes in the obsidian?
Local materialsLocal materials
Local materials

The walls are made of alternating obsidian and pumice
Towering piles of glassTowering piles of glass
Towering piles of glass

With occasional little additions on top...
Paulina PeakPaulina Peak
Paulina Peak

Seen from the Big Obsidian Flow. Paulina Peak is the highest point in this formation. You can hike to the top, and I think you can drive there, too, but we didn't.
Paulina LakePaulina Lake
Paulina Lake

Left pic in panorama threesome. This looks northwest.
View to the northwestView to the northwest
View to the northwest

Those wonderful Cascade Mountains still within sight from the glass mountain, which is NOT part of the cascades chain.
East LakeEast Lake
East Lake

Beach by campground--a better campground than at Paulina Lake, I thought.
East Lake 2East Lake 2
East Lake 2

View across lake to the volcanic barrier which partitions the caldera and divides the two lakes

16th August 2010

In New Mexico they are Apache Tears
Small pieces of the obsidian glass were used by the Native Americans, as you say, and also dissipated throughout the Southwest. They are considered a minor "find" when out hiking in New Mexico, and they go by the name "Apache Tears." I unfortunately think I gave mine to my Goddaughter back in the States. Glad you two are safe and having a grand time. Nice blog. Can't wait to see your video (which I am sure you are making also).
16th August 2010

Great Time~~~~
I'm Tiffany~~ I wondered how is your great time... I like your pictures. You look lucky!!!! I hope your travel is wonderful. take care~ see U~~~
16th August 2010

Hey Martha. That place looks very bleak. I would find it hard to keep smiling. I daresay it's a geologist's heaven. It's looking like spring in sydney.
17th August 2010

you're looks like very happy!! picture's very nice!!!
22nd August 2010

You sure know how to sightsee! Beautiful photos and memorable experiences. I am envious. Are you back home now? What's next?
31st March 2011

Hello, I love your article, but could you possibly tell me the cordinates of Glass Mountain? I need it for a science project, but miraculously no sites have them. Please help!
17th June 2011

wonderful blog
So enjoyed the down to earth, informative blog with the great pictures. Felt like I was there with you. Thanks for sharing

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