The "Sailing Stones" of Death Valley
If you venture a little further past the Ubehebe Crater in Death Valley National Park, you'll reach a crossroads: The road to Scotty's Castle, which has been closed since flooding in 2015, and an off-road path marked with this sign:
Should you brave the warnings, you'll forge ahead on a rough, rocky road full of sharp stones that takes you up and over the mountain, through a Joshua Tree forest, that, depending on when you go, may be studded with wild flowers.
At the end of the 26 mile rough road, is one of Death Valley's most unique features, and until just a few years ago, one of its great mysteries. Welcome to the Racetrack Playa.
The Racetrack is a dry lake bed. Most of the year, it is a broad, flat expanse of sun-baked mud in the shape of small hexagons, about 3 miles long and roughly 1.5 miles wide:
The only thing marring its eerily flat surface are scattered rocks, some extremely large, mostly concentrated at the south end. And that's where things get remarkable. The stones move!
Their mysterious journeys are captured in the dried mud, revealing long tracks that curve, sometimes bend sharply, and even criss-cross each other. In many cases, the stones sail parallel to one another:
Speculation on how, when, and why it happened went unanswered for years. No one ever saw them move. Sometimes they would go as much as a decade with no movement at all. But back in 2013, a team out of Scripps Institution of Oceanography, UC San Diego, discovered the answer.
Sometimes...it rains. Precipitation in the winter can transform the dry bed into a shallow lake less than 3 inches deep. If the temperatures plunge low enough at night, shallow ice can form that leaves the stones exposed. Under the sunlight, the ice sheets crack and shift as they begin to melt. If the wind is right, they blow the ice - and therefore the stones - across the Racetrack.
As the Racetrack is also an excellent location to shoot the Milky Way, we trekked out in the dark - with someone who knew the road well - to do some night sky photography in driving winds until about 3:30 in the morning, then hung around to watch the sun rise over the Playa. Given all the cracks in the lake bed and the muddled hexagon shapes, atypical of its usual appearance, we guessed there had been heavier rainfall than usual over the winter.
It's a beautiful, desolate, almost alien place to visit. The sailing stones are a truly unique phenomenon, worth the trek to see if you are prepared to safely travel the road that takes you there.
