What Are the Sailing Stones?
In a remote corner of northern Death Valley National Park lies the pancake-flat alkali basin called Racetrack Playa. Scattered across the cracked, ivory surface lie hundreds of dark dolomite and syenite boulders, some weighing as much as a refrigerator. Each boulder drags a shallow furrow in the mud behind it, some tracks stretching farther than a blue whale is long. Yet no visitor in living memory has seen these "sailing stones" in motion, spawning decades of campfire stories involving UFOs, wind spirits, and secret government experiments.
Native Tales and Early Visitor Reports
First Western mention arrived in 1915 from prospector Joseph Crook, who filed an informal report with the Inyo Independent describing "stones that walk at night." Indigenous Timbisha Shoshone narratives call them "rock children" who migrate when the Earth mother sighs. While poetic, the stories underscore a plain fact: the boulders clearly shift over time. Photographic evidence collected by the National Park Service between 1968 and 1970 shows single stones traveling a straight path, then making abrupt 90-degree turns, zig-zagging like drunken sailors. Mapping the plates by hand became a cult hobby for Los Angeles weekend adventurers in the 1970s and 1980s, but the mechanism remained stubbornly hidden.
Wind Alone Was Never Enough
The trail makers were thought powered by abnormally strong gusts. Simple physics said that would demand sustained 150-mile-per-hour winds—greater than a Category 5 hurricane—something never recorded inside the basin. Instruments placed at Racetrack Playa’s south end in October 1983 registered peak gusts of 74 mph during a winter storm. Not even enough to budge the smallest tagged rock. Adding plywood sails to the stones in 1975 experiments failed unless the stones were already sitting on a film of water, hinting that another ingredient was essential.
Thin Ice, Light Wind, and Slippery Mud
Scientific breakthrough arrived in 2011. Paleobiologist Richard Norris at Scripps Institution of Oceanography co-authored a paper in PLOS ONE after instrumenting 15 stones with GPS loggers. The team endured seven years of tiny batteries and harsh desert cold. They finally got their result on a December 2013 morning: ice-shrouded plates about one-eighth of an inch thick formed overnight. A light, 9 mph breeze snapped the sheet forward like a sailboat tacking, propelling stones at two inches per second. Because the sheet floats but stays anchored at its edges by contact with the ground, it drags the trapped stone along. The whole raft moves only for five to ten seconds at a time, after which it settles and has to wait until the next optimal weather cocktail.
Why These Exact Conditions Are Rare
Racetrack Playa is the catch-basin for an 80-square-mile watershed. A single cloudburst can lay down a mere three millimeters of water—just enough to flash-freeze at night when temperatures drop to the mid-twenties Fahrenheit. Combine that with sustained but mild wind the following morning and the stone may travel. The window is so precise that the stones move collectively once every several years. That is why thousands of hikers never see it happen.
New Visitor Destiny: GPS Tracks
Norris team’s real-time data revealed an elegant ten-second choreography captured on time-lapse. The Stones crept 15 feet over the frozen mud, turned against the breeze, and stopped abruptly as the ice sheet melted. Total distance recorded was 735 feet for the fastest stone during the single 2013 event. Later analysis of weather archives suggests the fleet of "sailing stones" on Racetrack Playa had last enjoyed similar conditions in 2009.
Copycats Around the Globe
Researchers using the same formula found that moving stones appear in at least four dry lake beds worldwide:
- Little Bonnie Claire Playa, Nevada - ice sheets too thin; only 3 rows of tracks have been found.
- Soda Lake, Mojave Desert - tracks average 30 meters and always parallel, indicating stronger and steadier wind.
- Etosha Pan, Namibia - calcium-carbonate shelf instead of silica mud; tracks slightly curved.
- Newberry Volcano Crater Lake playa, Oregon - stones reach 77 kg; tracks shorter due to coarse volcanic grit.
Each site tweaks the combination of water depth, ice thickness, rock size, wind pattern, and surface friction, proving the Racetrack Playa phenomenon is more common than once thought, just invisible to most humans.
Protecting the Desert Lab
In 2022 the National Park Service increased staffing on Racetrack Playa during permitted winter visitation. Off-trail foot traffic had begun to fill in the tracks by kicking loose fine silt. Rangers now deploy low-flying drones for mapping instead of tromping across the surface. The GPS-tagged stones continue to answer once-in-a-lifetime questions as every winter storm reloads the experiment.
Could Climate Change Silence the Stones?
As overnight frosts in Death Valley decline (data from NOAA’s Furnace Creek station show 20 % fewer sub-freezing nights from 1960–2024), the Racetrack Playa cocktail is becoming less potent. If cloudburst frequency also lowers, track-making episodes may shift into multi-decade gaps, making the stones appear permanently frozen in place to our descendants.
The Takeaway for Curious Travelers
No crystal skulls, no magnetic vortex, no ghostly night whispers—just cold, wet, wind, and the patience of years. The sailing stones are science in slow motion. Visit during late autumn and you may witness pooled rainwater freezing under starlight, setting the stage for the secret choreography that will not unveil itself until the glistening dawn.
Sources
- Norris, R. D., Norris, J. M., Lorenz, R. D., Ray, J., & Jackson, B. 2014. "Sliding Rocks on Racetrack Playa, Death Valley National Park: First Observation of Rocks in Motion." PLOS ONE. Doi:10.1371/journal.pone.0105948
- Reid, J. B., Jr., Bucklin, E. P., Copenagle, L., Kidder, J., Pack, S. M., Polissar, P. J., & Williams, M. L. 1995. "Sliding Rocks at the Racetrack, Death Valley: What Makes Them Move?" Geology, 23(9), 819-822.
- National Park Service. "Weather and Racetrack Playa Conditions." nps.gov (accessed 2025).
- NOAA Furnace Creek Weather Station historical climatology, data 1985–2024.
Disclaimer
Article created by an AI journalist from publicly available peer-reviewed sources and government datasets. Statements are current as of 2025 and are not an endorsement or guarantee of future research outcomes.