Mysterious Moving Rocks in Death Valley National Park

California is home to some pretty amazing natural occurrences! 

From ancient volcanoes to the tallest mountain in the contiguous United States to high-plateau deserts, towering Sequoias and more, the Golden State is a nature-lover’s dream that never ends. There’s so much to do, so much to see and, as with any ecologically diverse region, so much that we still don’t know about the jewel that is California State.

One of California’s most fascinating mysteries has gone unsolved for nearly a century, leaving scientists and geologists stumped at a near-alien phenomenon that takes place in the heart of the Mojave desert — Death Valley’s sailing stones.

Here’s everything you need to know about the mysterious moving rocks that appear every few years out of nowhere in a scorching, waterless lake bed.

Racetrack Playa’s sailing stones

Racetrack Playa

One of Death Valleys’ greatest wonders are the moving rocks of Racetrack Playa, a phenomenon that, until quite recently, has baffled and mystified geologists for over a century. 

Racetrack Playa is an ancient lakebed located in the northwestern section of Death Valley National Park. The 4.5-mile-long playa once contained water that has long since evaporated, leaving behind a lakebed covered in dry, cracked mud dotted with the occasional boulder and debris that have made their ways down from the jagged, rocky mountains surrounding the lake. 

Traveling stones first observed

It’s here that the moving rocks were first observed in the early 20th century by prospectors and geologists traveling through the area. A visitor to the playa in 1915 noticed that some of the isolated rocks in the center of the dry playa had long trails extending from them, with no apparent evidence of interference hinting to the cause. 

These rocks appeared to have traveled across the playa and left tracks in their wake, sometimes reaching as long as 330 feet. 

This phenomena was again observed a few decades later by geologists who began monitoring the stones and their tracks, though with movement only occurring every three years or so, it was difficult to determine the exact cause of the mysterious moving rocks. 

Monitoring the moving rocks

Park rangers began monitoring the rocks in earnest in the 1950s, recording the track lengths, furrow depths and directions of movement whenever they appeared. The 1970s brought about the first official monitoring program assigned to Death Valley’s moving rocks — each rock was assigned a name, and stakes were placed throughout the playa to act as measurement references for any movement. This program lasted around 7 years, and though it yielded plenty of data for every occurrence, geologists were no closer to discovering the cause of the mystery.

It wasn’t until 2009 that scientists finally had access to technology that would help them truly capture the strange phenomenon. Namely, inexpensive time-lapse cameras. 

These time-lapse cameras were stationed around the playa to capture any movement that occurred. Of course, having cameras running for years at a time on the off chance of capturing moving rocks is quite the undertaking, so the cameras were outfitted with wind-triggered systems that would only set the cameras recording if wind was present. This cut out thousands of hours worth of footage that would not likely reveal any results, simplifying the process considerably for the geologists, park rangers and scientists who were desperate to figure out the mystery of Death Valley’s traveling rocks.

Solving the mystery of the sailing stones!

Finally, the mystery was solved in the winter of December 2013-January 2014, nearly a century after the moving rocks were first discovered by travelers so long ago. 

On the night of December 20, 2013, winter precipitation and condensation created a shallow pond across the playa that measured no more than three inches deep. The pond was deep enough to form floating ice but shallow enough for the many rocks on the playa’s surface to stick out above the water.  

The cold nighttime air caused the water to freeze into floating ice on the surface, ice that was thin enough to move about on top of the liquid water below but thick enough to not break apart.

As night turned into day and the sun rose, the ice began to melt and break into large sheets, similar to how icebergs break off larger icebergs as temperatures rise and ice weakens. These sheets floated above the water below and, combined with a light wind funneling through the valley, glided across the surface of the water until it melted under the hot afternoon sun.

The rocks trapped in the center of these ice sheets glided along whatever path the wind took the ice, leaving tracks in the soft mug below as the ice shoved and rolled rocks downwind. 

In the nearly three months that the pond existed over Racetrack Playa between December 2013 and February 2014, scientists observed around 60 rocks move five separate times as the ice froze, moved, melted and froze again. Some rocks moved a total of 735 feet across the playa over those few months, leaving zig-zagging tracks behind as wind direction, ice movement tumbled the rocks over and drove them across the soft mud. 

The mystery that had been plaguing and stumping scientists all over the country for decades had finally been solved, and today visitors to Death Valley National Park can see the long, meandering trails of these traveling stones stitched into the hard-caked mud of the scorching playa for themselves! 

If you live in our Southern California apartments, then a trip to Death Valley National Park is a must-do for any outdoor enthusiast. Not only is it one of the hottest and most extreme places on the planet, but its sailing stones are a one-of-a-kind phenomenon that is unheard of anywhere else in the world. 

Enjoy!

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Featured photo courtesy Wikimedia/Giuseppe Milo