The Devil’s Postpile National Monument: Wondering around the Eastern Sierra Nevada never ceases to amaze. The humbling power of the Earth’s tectonic strength is fully on display, just under the soles of your shoes. There’s hot springs, volcanic rubble, cinder cones, escarpments, forests being choked with magma gases rising from the ground around their roots and, if you look hard enough, remnants of a super volcano caldera.
Another example of this rumbling, geology-on-demand is a display of tightly packed rock columns, with neatly-spaced beveled edges and curious geometric symmetry that suggests some kind of a geologic pasta extrusion process.
But the rock columns at the Devil’s Postpile weren’t extruded at all. They’re the result of basaltic lava that flowed into the valley some and then cooled into some 60 ft (18 m) columns of 6 sides, with each of the corners set at an angle of 120º. (a.k.a. ‘columnar basalt’)
So it begs the question how has nature managed to create this wonderful geometric order in this otherwise totally chaotic geologic neighborhood?
Without digging too deep (pun intended) into the science, it has something to do with thermodynamics and materials science, and as it turns out, the hexagonal, six-sided, 120º configuration is the most efficient geometric pattern for relieving the thermal stress of the cooling process.
The cooling at Devil’s Postpile began sometime between 80,000 and 100,000 years ago after what we know today as the Red Meadows Valley was filled with basaltic lava some 400 feet deep. Over time, glaciers and river erosion carved out the valley we see today, exposing the columns to daylight, and earthquakes. As sections of the columns broke away they collected at the base of the feature into what is called a talus slope.
These fallen columns have tumbled down the hillside to the edge of the trail and recall the rubble at an ancient Greek temple. As a practical matter, these broken bits, which could almost pass for pre-cast concrete, have been recycled to line the walking paths along the base of the feature.
When you take a trail to the top the columns, the geometry is on full display up here. The column tops have been scraped smooth and polished by the glaciers for your viewing pleasure, which just adds to the wonderment of the park’s experience.
From the top of the postpile feature, you get views to the other side of the valley. Other features in the area include Rainbow and Minaret Falls, Soda Springs, Mammoth Mountain and the Red Cones.
We timed our visit to just to the middle of October, which is just after the busy summer season and before the autumn leaf viewing and ski seasons start. We also got to the park early, before the busses started running, and were able to drive to parking within a short walking distance of the columns.
But wait, there’s more: This isn’t the only ‘column’ thing in the neighborhood. As Susie and I were driving over Sonora Pass (CA 108) on the way to the Postpile area we stumbled upon the Columns of the Giants park and trails (technically an ‘NRT’ or National Recreational Trail). Read about that visit here.
Other examples of basalt columns are at Devil’s Tower in Wyoming, the Giant’s Causeway in Northern Ireland, and Svartifoss in Iceland.
Photo Factor: I’ll cut right to it; bring a polarizer in your kit to photograph these formations. A combination of flat, reflective surfaces and the often very bright California sunlight really makes for a super high-contrast situation. On my next trip I’ll use the tripod where practical and make a series of bracketed exposures so I know I can get something out of the shadows, instead of relying on crushing the highlights and raising the shadows in editing. You will also want to bring a longer mm lens to get some detail shots of the columns, otherwise you’ll have to scramble over the talus tailings at the base of the features, and that doesn’t strike me as much fun with any amount of camera gear. I’ll always bring along a flash unit as well, to fill in the shadows on some closer detail shots; I always bring a flash unit or two whenever I set out on these adventures in California anyway.
