The Mysterious Sailing Stones: How Rocks Can Move Unaided Across the Desert

Written By Wise Healthy n Wealthy

How do stones heavier than humans glide across a dried lake bed without leaving any sign of how they got there?

At Racetrack Playa in California’s Death Valley National Park, you can see these rocks speckling the arid surface. Trails extend considerable distances behind them – as if they’ve been dragged (sometimes hundreds of meters) by some invisible force.

To the casual observer, there’s no obvious explanation for those drag marks.

It’s as if the stones have moved of their own volition, like museum exhibits that come alive when nobody’s watching, then freeze when you turn to look.

They’re nicknamed “sailing stones” or “walking rocks,” and the phenomenon remained a mystery for over a century. It was only solved when someone had the bright idea to film a timelapse in 2014…

Find out how these huge stones move unaided through the desert below.

A Brief History of Sailing Stones

In 1915, a prospector from Nevada called Joseph Cook visited Racetrack Playa and recorded this phenomenon for the first time.

More than thirty years later, it featured in a report written by two geologists who had taken an interest in the area. In it, they speculated that strong gusts of wind could be causing the stones to move if conditions are muddy.

Interest grew thereafter, controversy over the truth mounted, and people sought out other locations where the phenomenon occurs, so they could study it there, too.

The mysterious sailing stones come from the mountains you see in the distance. Photo Credit: Shutterstock.

Where Do the Stones Come From?

The mountains surrounding Racetrack Playa are comprised of dolomite and syenite. Sailing stones are composed of these types of rocks, too.

When the mountains erode, the rocks get dislodged and tumble to the ground below. Once they’re at the surface of this scenic dry lake, they’re apparently free to roam!

Previous Sailing Stone Theories and Research

Several theories about sailing stones have been posited and debated since the mid-20th century.

Some of the more farfetched included paranormal explanations (like aliens) and unknown magnetic field effects. A more popular idea was that high winds propel the stones forward in wet/muddy conditions. However, others argued the stones are too heavy for that to make sense – some of them weigh as much as a person.

In 1955, someone called George M. Stanley suggested that ice sheets could form around the stones, somehow triggering the movement.

Research in the 1970s tested these ideas, but, despite a seven-year study of rock movement, was inconclusive. Studies in the 1990s had more success, proving that ice floes (sheets of floating ice) played a role, and that the stones feel the full impact of high winds made more intense by the landscape’s smooth and flat surface.

However, it wasn’t until the 21st century that the phenomenon was finally solved for good.

Mystery Solved: Why the Sailing Stones Move

Ultimately, technology solved this mystery. Past studies had suggested the stones only moved about once every three years, and only for around 10 seconds each time.

That made monitoring them for movement incredibly difficult. Until that is, things like time-lapse digital cameras, wind-triggered imagery, and GPS came along.

Suddenly, scientists could capture what was happening and track everything using GPS.

In December 2013 and January 2014, this technology came together to show what was going on. It was a time of intense rock movement, when more than 60 of them moved – sometimes more than 220 meters in total.

It wasn’t a combination of strong winds and thick ice, as people had suspected.

Instead, rainfall formed a pond, which froze overnight to form a thin ice sheet over the lakebed. When sunlight hit that ice the following morning, it started to thaw. The ice sheet broke up into enormous panels of ice a few millimeters thick atop the water’s surface. A light wind then pushed the ice sheets forward, shoving any stones in their way in the process.

Here’s a great video showing this in action.

So, there you have it: a centuries-old mystery solved.

The sailing stones of Racetrack Playa shift across the lakebed not through supernatural forces but by a specific balance of water, wind, and ice.


This post first appeared on Travel and Intrigue.

Leave a Comment