Rocks That Leave Tracks in Death Valley
On the dry lakebed of Racetrack Playa in Death Valley, rocks leave long, winding tracks. Their movement is not mysterious: in winter, rain can form a shallow pond that freezes into thin sheets of ice. As the ice cracks and drifts in a light wind during the day, it pushes rocks across the wet clay.
AI-generated synthetic educational illustration: a rock and its track on Racetrack Playa, with a diagram of wind moving thin ice and a rock. It is not documentary photography or a depiction of a specific observed event.
Researchers directly recorded rocks moving for the first time in 2013–2014. Instrumented rocks shifted in light winds as thin ice panels moved across the shallow pond. The movement requires a rare combination of water, freezing temperatures, and wind, so it is easy to miss.