The Sailing Stones of Death Valley: Are the Rocks Alive?

Beneath the blistering sun of Death Valley – the hottest and driest place in North America – the cracked, parched earth stretches endlessly, resembling a vast, desolate canvas. This landscape, forged by immense geological forces around sixteen million years ago, is a realm of extremes and enigmas. Yet among all its mysteries, one phenomenon stands out above all: stones that appear to move on their own, silently traversing the desert floor, leaving haunting trails in their wake. Welcome to the enigma of the Death Valley sailing stones.

So how do these rocks – some as small as marbles, others weighing as much as a fully-grown male tiger – move unaided across the Death Valley floor? Is it science, or the supernatural? Are these mysterious rocks somehow alive?

Let’s take a trip to the California-Nevada border in an attempt to uncover the mesmerising mystery of the sailing stones of Death Valley.

The walking stones of Death Valley are a geological phenomenon, but where exactly are they located? They’re actually found in an area known as the Racetrack Playa, which is a dry lake in the northwestern part of Death Valley National Park in California’s Inyo County. It’s roughly five kilometres long and two kilometres wide, and receives as little as five centimetres of rain each year. The dry lake has no vegetation and is almost perfectly flat. It’s bordered by ranges up to 1,700 metres tall, and the surface is mostly dried, fine-grained clay in the shape of hexagons. It’s also littered with moving rocks. It’s fair to say then that Death Valley is an unusual place, but just how unusual?

While it’s possible the sailing stones may well have been doing their nightly dance for millions of years, observations of these mysteriously moving rocks date back to the early 1900s, when visitors and local miners in Death Valley began noticing long trails etched into the dry lake bed behind seemingly stationary stones. The first documented account of the walking stones of Death Valley was from 1915, when, it’s thought, a Nevadan prospector noticed the phenomena.

Scientific interest in the sailing stones began to gain momentum soon after World War II. In 1948, geologists Allen Agnew and Jim McAllister mapped the area, noting the lack of a clear explanation for the stones’ movement, and published their findings in the Geological Society of America Bulletin. They thought the movement was caused by strong gusts of wind.

In the 1950s, researchers began to study the trails in more detail, documenting the length and width of the furrows, as well as their general course. Their aim was to simply record the evidence rather than speculate on how the stones were moving, but the 1950s was the beginning of the Space Race so naturally, speculation shifted from the scientific to the unexplained…

Most geologists at the time believed to some degree that strong winds and, on rare occasions, wet mud, could work in tandem to move the stones. Others couldn’t quite come to the conclusion that wind alone could move a 300 kilogram rock.

As is normal where unexplained (seemingly) natural phenomena are concerned, such as the Bell Island Boom from Newfoundland, the Brown Mountain Lights from North Carolina and the Taos Hum from New Mexico, explanations included everything from pranksters to more fantastical possibilities.

Were the stones being moved by bizarre magnetic forces? An otherworldly psychic energy, transdimensional vortices, or even alien spacecraft? While entertaining, the true explanation is unlikely to be found in an episode of The X-Files and more likely to be in the pages of a geology textbook.

Between the late 1960s and the 1990s, extensive studies of the Death Valley moving stones were undertaken. One monitoring study by famous geomorphologist Bob Sharp assigned names to the stones, and they were tracked over a period of seven years. One stone, named Mary Ann, moved 65 metres in the first winter, and the smallest stone, Nancy, moved a cumulative distance of 260 metres.

During the 1990s and 2000s, researchers proposed various theories involving strong winds, slippery clay surfaces, and even thin layers of ice, however, definitive evidence remained elusive until 2014.

In 2014, the long-standing mystery of the sailing stones of Death Valley was finally unravelled by a team led by paleobiologist Richard Norris of the Scripps Institution of Oceanography at the University of California, San Diego.

The study, set up in the winter of 2011, involved fitting fifteen rocks with motion-activated GPS units, and installing a high-resolution weather station alongside time-lapse photography cameras. They then had to wait for something to happen. During a rare sequence of weather conditions in the winter of 2013 – 2014, the researchers were finally able to witness and record the stones actually sliding across the playa’s surface for the very first time.

Richard Norris said, ‘Science sometimes has an element of luck. We expected to wait five or ten years without anything moving, but only two years into the project, we just happened to be there at the right time to see it happen in person.’

Their study, published in the peer-reviewed journal PLOS ONE in August 2014, confirmed that no mysterious forces or extraterrestrial activities were at play. Instead, the stones’ movements are the result of a rare and intricate interplay of environmental factors that occur very infrequently at Racetrack Playa.

How Do The Death Valley Sailing Rocks Move?

The Death Valley stones move under an incredibly specific set of natural conditions involving water, ice, and wind. The researchers discovered that, under the right conditions, a shallow layer of water occasionally accumulates on the playa’s flat surface. On cold nights, this water freezes into thin sheets of ice. When the sun comes up and the ice warms, it begins to melt and break apart into large floating panels. When light breezes blow – sometimes as gentle as three to five miles per hour – the ice panels nudge against the rocks, causing them to glide slowly across the wet, slippery mud beneath. This movement is gradual and can last between several seconds and a few minutes, but it’s subtle enough that it had eluded direct observation for decades.

This extraordinary research not only demystified the enigma of the Death Valley sailing stones, but also highlighted the intricate and often surprising processes that can shape the world around us. Thus, what was once a baffling enigma now has a definitive scientific explanation – no paranormal phenomenon or alien portals required, just the subtle workings of mother nature slowly and patiently shaping our world.