After a few days backcountry ski touring around the Mammoth Lakes region I was feeling pretty tired, so I opted for an “active” rest day exploring a nearby area I’d driven past a zillion times, but never been to: Obsidian Dome. Looking for a low-key natural area I could explore and enjoy the sunshine, what I stumbled on was a geologic wonder that sparked the old joy of my days at the USGS/Environmental Sciences.
(I was lucky to enjoy any rest day activities at all, as the day before I’d set out from town after our tour in search of a campsite and managed to high-center my car on a snowbank far off-road. Normally that wouldn’t be an issue, except this also coincided with the cell towers being down on the Eastside… what timing. I spent well over an hour hacking at the ice and snow with my shovel and ice axe before by dumb luck, an off-roader happened by exploring the area (the only car I’d seen in hours) who had a tow strap in his truck. Sleeping in the car this trip I had everything I needed to survive another week but damn was I glad to be out, I owe ya Brandon!)
A quick drive north from Mammoth brought me to the entrance and staging area, which had a few other folks sledding around the parking lot or get ready to head out. For a weekend it was really uncrowded, a nice change of pace from the zoo that Bishop/Mammoth can be. The nearby area is popular in winter with snow-mobiles, but they limit motorized traffic in this zone so it’s easy to enjoy some peace and quiet. The trails are also groomed for cross-country ski use (though not super well maintained, which is maybe for the best).
Without proper cross country skis I threw my lightest touring setup on and grabbed some quick provisions for the day, mostly my GoPro and some snacks, setting off for adventure. The lack of cell service leading up to this left me unsure what to expect, and it was great to be “really” off the grid (as long as I didn’t get hurt). All I knew was that this area was the site of quite a bit of volcanic activity, and given the name, I’d probably come across some obsidian.
Skiing a few miles in I came across the main formation, a large dome on the left hand side of the trails. Conditions were beautiful, the sun was shining, and I only saw one other person out snowshoeing. The world was my oyster today: should i loop the trails, maybe climb a nearby peak, ski some sick lines, or check out the dome? Being solo I opted for the dome, hoping it would afford some fun adventure without exposing me to too much risk (the snow felt settled and I probably could have skied some lines nearby, but 1) that would defeat the rest day idea and 2) I did encounter some solid wind slabs, so avy danger was not totally nonexistent).
Scoping the slopes most of the initial areas I came across were too steep and I had reservations about the snow stability. I was also thinking a lot about where I’d chose to put my skintrack up the face: the snow was beautiful and undistributed, and while the park was fairly empty I didn’t want to ruin anyone’s view of this thing with a big ugly skintrack up it’s face. Continuing on I found a snowed-over access road that wound up the formation, an easy and safe way to the top. What would I find up there? Only one way to find out!
(Geology insert: just what is this place I was exploring? From Wikipedia:
The Mono–Inyo Craters are a volcanic chain of craters, domes and lava flows in Mono County, Eastern California. The chain stretches 25 miles (40 km) from the northwest shore of Mono Lake to the south of Mammoth Mountain.
The Long Valley to Mono Lake region is one of three areas in California that are in the United States Geological Survey's volcanic hazards program. These areas are in the program because they have been active in the last 2,000 years and have the ability to produce explosive eruptions.)
Up on top of the formation was beautiful, this winter had provided an immense amount of snow and only portions of the rock piles were visible. Strong winds had formed all kinds of crazy sculptures: cornices, snow bridges, and warping snow features of every shape and size imaginable. Views towards the Sierra and Mammoth crest were gorgeous on such a clear day, and immediately sparked my favorite feelings about being in the best mountain range on the planet (in my humble opinion at least haha).
After a quick bite (protein cookies are the best, you feel healthy eating something so delicious!) I set off drifting about, checking out each cool thing I saw with the freedom and relaxation of someone with no agenda, no time crunch, and no concrete plans. I’d follow a raven around for a bit, sit with the tiny weather-beaten bonsai trees that clung to life up there, and of course eventually made my way to the local high-point (something so natural compelled me to keep scrambling up and up until I found myself on the closest thing you could call a “peak” here).
Having found the high point (completely by accident, I’d simply scrambled to a ‘cool’ spot and found the marker) it was time to nerd out some some sweet rocks. Gosh, isn’t nature just neat! While to everyone else they might just be ‘rocks’, to me this was an amazing collection that tells the story of a powerful, sometimes violent past, forged in cataclysmic events reaching up from the earth, and with a rich human history as well. From the USGS:
Obsidian, Glass Creek, and Deadman Creek domes all erupted in 1350 CE (Millar, et al. 2006). The vents from which the domes erupted are all aligned to the north-south. Based on the north-south alignment of the vents, the magma that fed these eruptions was most likely brought to surface along a dike(Miller, 1985). A dike is a long crack that is filled with magma - think of it as a curtain made of magma.
The eruption date for the Deadman Creek, Glass Creek, and Obsidian domes is one of the best constrained prehistoric eruption dates in the world. Using tree rings, Millar and others, found that the eruptions occurred in late summer 1350 CE.
It’s hard to capture in pictures, but the rock definitely had the jet-black glass-like sheen to it in many spots. That would be juxtaposed right nearby with other ferrous (iron-containing) samples that had rusted out into weird bubbles, and everything in between. The more I explored, the more I liked the idea of trying to locate my minds eye version or platonic ideal of the perfect obsidian rock. Something void of color, like a black gemstone, that would represent this place perfectly. A sample that could be carved and offered to the gods/neighboring tribes if this had been slightly more ancient history. From the peak, I scoped a few potential sights with the best rock, and set off to see what I could find.
After exploring a few piles, and with the day winding down, I finally came across what I was looking for. The blackest of all the piles, this area yielded amazing rocks that were like peering into a shining abyss, somehow full of nothingness and shining without light. I poked around for the best one and eventually settled on this shaft, something that you could easily see fashioning into a ceremonial weapon, or maybe just a grand bookshelf centerpiece. However, though I was really tempted to bring it or even just a tiny sample back with me, I resisted the urge, instead spending my time with it and then returning it to the pile. While I’d love to have it in my collection and there’s nothing really wrong with that (there’s plenty of rocks there) it just felt right to stick by that cheesy principle of ‘take only pictures leave only footprints’. I’m also rather superstitious when it comes to accidents in some of my outdoor sports, and it just didn’t feel like the time or place to provoke any ancient rock gods that might be watching the place.
Soon it was time to say goodbye and get back to the car. Partway back cell service was restored, and I had the most jarring experience of being wrenched back into the real world. After a beautiful outside with no one to keep me company besides some nifty rocks suddenly everything was Instagram updates and email notifications, which was pretty hilarious and to be honest kind of nice. That said, this day was a magical experience I won’t soon forget, and would urge you to stop and check the place out next time you’re in the area!