Shields of calcite in Lehman Caves
This past week or so I have been pondering quite ponderously how to proceed with this blog. I’ve completed my 5-month summer NPS job at Katmai in Alaska and so the uniqueness of my being in that location has disappeared and I have returned home. Home, however, is the Colorado Plateau/Great Basin transition zone, an area of the southwestern United States of unique geology and jaw-dropping scenery. There are so many extraordinary places to which I can drive in less than a day (and write about!) that it would take a thousand lifetimes to explore them all. Actually, walking or riding a bicycle could get me to some pretty fantastic places, too, but I would definitely need several additional lifetimes utilizing those modes of transport. So I will just keep on traveling and writing about My Backyard (and beyond), and hope that my journeys continue to keep you engaged.
A favorite nearby locality of mine is Great Basin National Park near the Nevada-Utah border. This jewel of the desert is barely 200 miles from home and I can drive there in about three or so hours without even having to go through a single stoplight if I route myself through Panaca and Pioche, Nevada. These two-lane roads are given names such as “The Loneliest Highway in the World” and have signs reading “Next Gas - 100 Miles” so you’d better fill up when you can (gasoline and tire pressure) and bring a cooler full of sandwiches and drinks.
Lehman Caves extends a quarter-mile into the flank of the Southern Snake Range in Great Basin NP. According to the park brochure it was “discovered” and explored by Absalom Lehman in 1885 but of course Native Americans knew about the cave long before any white person ever saw it. Over the past 15 years I’d hiked in both the Northern and Southern Snake Ranges (the park is in the Southern) and gone on several geology field trips (mainly in the Northern) but had never taken the cave tour. Where have I been??? So last weekend, after being home from Alaska for a grand total of five days, I got my friend Lucy to go along on an overnight “sandwich camping” trip where we’d take the cave tour on Friday, pitch our tents at the 9,886-foot elevation Wheeler Peak Campground, and hike up the trail as far as our little feet would carry us to Wheeler Peak (at 13,063 feet) on Saturday.
Lehman Cave is what’s called a solution cave. Over hundreds of thousands of years, ancient carbonate limestones, remnants of Paleozoic seas, were dissolved at the water table by acidic surface waters mixed with waters from deep below the surface. This acidic water dissolved the limestones and enlarged openings already present along bedding planes, fractures, and faults in the rock. In this way the caves eventually formed. As the water table dropped over time with the end of the last Ice Age, air-filled caverns emerged. Stalactites, stalagmites and other types of formations were created as dripping waters leaked into the now air-filled caves. Large thin round discs or shields of calcite are seen throughout the cave system and present a very dramatic sight as they “drip” downward from the dark recesses of the cave’s barely discernible ceiling.
A ranger with NPS guided our the 90-minute tour – only 20 people at a time are permitted and even in late Sept. our tour was full. I had another personal agenda for spending a few days at Great Basin – back in late winter I had applied for a seasonal NPS job there, but by the time they called me (in April) to see if I was interested I had already accepted the job at Katmai. So I wanted to meet with the woman I’d spoken with in April, and put a face to a name so that I would be remembered the next time my application floated across her desk. My efforts paid off and we were able to spend a nice bit of time chatting. I discovered that Great Basin NP has several permanent park ranger positions in addition to their seasonals. So naturally I will watch for the job posting and see what the future brings. I totally would love to work at Great Basin permanently – it’s close to home and the geology of the region fascinates me.
The water at Wheeler Peak campground had been turned off due to cold weather earlier in the month but that didn’t deter Lucy and me. We had a couple gallons between us and planned on heating water only for coffee and hot chocolate. That evening at dinner we ate cold beef out of the can (it was really good!) along with sliced veggies, cheese, and fruit. The sky was clear and later I gazed through the spruce trees at the night sky for which Great Basin prides itself. It wasn’t the Valley of Ten Thousand Smokes, but it was pretty good.
Wheeler Peak is the second highest peak in Nevada (after Boundary Peak at 13,143 feet). The well-maintained trail, 8 miles round-trip, at first climbs through stands of aspen, reaching timberline where stunted and twisted limber pine and Engelmann spruce struggle to survive. Above timberline the trail becomes more exposed to the elements as it works its way through the bare cobbles and small boulders of quartzite and conglomerates. I know the math here: fierce winds + Wheeler Peak = no hike. But this Saturday we realized how lucky we were that the wind and sunshine deities favored us, so we enjoyed the far-reaching vistas of the Basin and Range as we continued on up the mountain.
There is a remnant alpine glacier on Wheeler that covers only about 50 acres and it is one of the most southerly in the continental US. I used to hear stories of people hiking up to the summit of Wheeler and coming down via the glacier. Not this girl!
At the saddle (11,800 feet) I wondered where those pesky little oxygen molecules had gone. I was becoming a little lightheaded and so decided that I had gone far enough. Lucy was soldiering on up the trail – having ridden cross-country on a bicycle the previous summer she is in quite better shape than I am. Some three-sided rock shelters had been constructed on the saddle to act as wind-breaks, so I parked myself in the lee of one of them and comfortably ate my lunch. I examined the rocks while I sat, looking for any sheared schists or stretched conglomerates, evidence in the Snake Ranges of what geologist call a metamorphic core complex. Here, the underlying crystalline rock was arched upwards into a dome during tectonic activity while overlying rocks were stretched into blocks and transported to either side of the dome.
I was gazing into the Basin and Range. Mountains and Valleys as far as the eye could see reached beyond the western horizon across Nevada all the way to the Sierras. It is a special place, this Basin and Range Physiographic Province. The Great Basin, in which there is no surface drainage of water to the oceans, is enclosed by it. One early western explorer called the mountains of the Great Basin “marching caterpillars” and once you spend some time here you begin to understand why. They are oriented generally north-south, and there are upwards of 300 discrete mountain ranges in Nevada alone, more than in all of Alaska.
With my binoculars I watched Lucy work her way up to the summit. I received intermittent reports from folks coming down that she was doing just fine. I did consider continuing on up, but when two guys came down and related it had taken them and hour and a half to reach the summit from the saddle I decided it was too late for my assault on the summit since the wind had picked up and there was lightning and thunder on some distant peaks.
When Lucy was almost back at the saddle I started down, figuring she could easily catch up with me. We met up again at treeline, the trail above through the cobbles and small boulders of quartzite giving way to the softer soils in the spruce and then aspens. We came upon four deer on the trail that were not startled by our appearance and seemed not to be bothered by our presence. A small curve of a rainbow followed us down the trail for a few minutes and then disappeared into the clouds.
It was cold canned chicken instead of beef for dinner this time. “Sandwich camping” involves no cooking but that night it was cold enough to wish we had something hot to eat. Laziness won out over comfort, however – we just didn’t want to go to the effort to cook. The next morning, though, after a wind-screaming-through-the-trees night we did the time-honored camping thing and just packed it all up and went down the mountain into Baker, NV for a breakfast of eggs and coffee that someone else cooked for us.
My goal is to make it to the summit of Wheeler the next time I go, for I know there surely will be a next time. I just can’t help and go back to the Great Basin whenever I can – and who knows? Maybe the future will find me working there. If so, I'll take you on the tour!