One of the places that captivated my attention early in life was the Racetrack, or playa, in Death Valley. This is where the moving rocks – aka sailing stones, rolling stones, sliding rocks, peripatetic rocks – move.

The Racetrack is a dry lakebed, and the moving rocks did just that – they moved across the playa, leaving tracks behind them. The problem was that no one ever saw them move. And these rocks were boulders, not little pebbles.

It has been one of the mysteries of Death Valley since the early 1900s. Many a scientist has come up with possible causes and solutions, but none was ever proven, until recently.

As a kid in junior high, this premise inspired me to write a short story for a literary contest. My solution was that this area was the folly of aliens in spaceships who used lasers to move the rocks in a game. They would swoop in, move the rocks around, and disappear as fast as they came, only to leave the humans below dumbfounded once again. I actually won the contest and scholarship for my story.

The tracks that the rocks leave behind differ in length and direction – which led to even more confusion. If it was wind that was proposed in a theory, the theory was thrown out when this type of tracking occurred. And it was illogical that wind could move a rock that weighed several hundred pounds.

Gravity couldn’t explain it since the rocks sometimes moved uphill. Earthquakes were not a factor. People and animal intervention were both ruled out. (My alien theory was looking pretty good.)

To add to the confusion, sometimes rocks would turn over, leaving a different type of track behind it. Some rocks would travel together, then one would abruptly change direction. In some instances, the trails would lead right to the boulders that caused them, and in others – well, the rocks just disappeared.

Tall tales prevail all over Death Valley, including one involving squirrels with super-human strength that push the stones together to use as shelter in difficult winters.

There seemed to be no hypothesis that would cover all these circumstances. Linear gullies were spotted on Mars, and it was thought that this was a similar geological phenomenon. However, it was determined that the Mars rocks were traveling on layers of gas – so this theory couldn’t be applied to our earthly rolling stones.

A NASA scientist in 2006 compared our rocks to those on Titan, a moon of Saturn. Titan’s rocks moved on a hydocarbon lake. He devised an experiment where he froze about an inch of water with a rock embedded in it. He placed this slab of ice and rock on a bed of sand in a container of water. He blew on the rock, and it moved. As it moved, it imprinted the sand.

This was the first successful experiment with the water-ice-wind theory.

Wind was suspected again and again in geological theories. In a study done from 1987 to 1994 by Hampshire College, wind alone was ruled out as the force behind the moving rocks. It was determined that a 44-pound rock would take a sustained, 175-mph wind to move it, and it would take a 280-mph wind would move the largest rock, which weighed 700 pounds.

Scientists now believe, more or less, that the rocks are moved by a combination of ice sheets on the playa, ice collars that form around the rocks, water, and low winds acting together to move the rocks. This phenomenon is known as ice shove.

However, this ice theory is not solid. Video footage has shown rocks moving at low wind speed within a flow of thin, melting sheets of ice. But due to the area’s microclimates, each rock could move due to different forces. Like aliens playing a game, perhaps.

Dianne Erskine-Hellrigel is executive director of the Community Hiking Club and president of the Santa Clara River Watershed Conservancy. If you’d like to be part of the solution, join the Community Hiking Club’s Stewardship Committee. Contact Dianne through communityhikingclub.org or at zuliebear@aol.com.