Mystery of Death Valley ‘Racetrack’ Rocks Is Solved

The phenomenon of the “sailing stones” on Racetrack Playa in Death Valley National Park has baffled scientists for decades. By some mysterious force of nature, rocks move along the flat-as-a-pancake playa and leave long trails behind. What causes the stones to move? One popular theory was that strong winter winds upward to 90 mph combined with just enough rain to make the clay slippery caused the stones to “sail.