Sailing the Racetrack Playa of Death Valley, California

No, this isn’t another travel post… It’s rocks doing the “sailing” this time.

These are moving rocks, also known as sailing stones, that mysteriously move across the surface of the Racetrack Playa, a seasonally dry lake (or playa) in the Panamint Mountains, Death Valley National Park. Most of the racetrack rocks originate from the nearby hillside of dark dolomite on the south end of the playa. As they move without human intervention, the rocks leave long tracks behind them, often tens of hundreds of feet and typically less than an inch deep. The rocks move once every two or three years and most tracks last for just three or four years. Rocks with rough bottoms leave straight striated tracks while those with smooth bottoms wander.

During periods of heavy rain, water washes down from the nearby mountain slopes onto the playa and form a shallow short-lived lake. Soon, the thin veneer of water evaporates and leaves behind a layer of soft gooey slippery mud. As it dries the mud shrinks and cracks into a mosaic of interlocking polygons.


Geologists have long speculated on the explanations of this very cool phenomenon. Most favor the idea that strong winds (nearing 90 mph) push the rocks along the playa’s muddy bottom left at the end of the rainy period. However, some of the stones are thought to be too heavy (weighing as much as a human) for the area’s wind to move. Some geologists maintain that ice sheets around the stones may help to catch the wind or move in ice flows. But both theories don’t explain how two rocks right next to one another can move in opposite directions or one can stay put while another three times its size doesn’t.

Ahh… the mysteries of Nature. I guess you can’t judge a rock by its mantle.

Nina Munteanu is an ecologist and internationally published author of novels, short stories and essays. She coaches writers and teaches writing at George Brown College and the University of Toronto. For more about Nina’s coaching & workshops visit www.ninamunteanu.me. Visit www.ninamunteanu.ca for more about her writing.