The mysterious moving stones of the packed-mud desert of Death Valley have been a
center of scientific controversy for decades.
Sailing stones, sliding rocks, and moving rocks all refer to a geological phenomenon
where rocks move in long tracks along a smooth valley floor without human or animal
intervention. They have been recorded and studied in a number of places around Racetrack
Playa, Death Valley, where the number and length of travel grooves are notable. The
force behind their movement is not confirmed and is the subject of research.
Rocks weighing up to hundreds of pounds have been known to move up to hundreds of
yards at a time. The stones move only every two or three years and most tracks develop
over three or four years. Stones with rough bottoms leave straight striated tracks
while those with smooth bottoms wander. Stones sometimes turn over, exposing another
edge to the ground and leaving a different track in the stone's wake.
Trails differ in both direction and length. Rocks that start next to each other may
travel parallel for a time, before one abruptly changes direction to the left, right,
or even back the direction it came from. Trail length also varies – two similarly
sized and shaped rocks may travel uniformly, then one could move ahead or stop in
Some scientists have proposed that a combination of strong winds and surface ice
account for these movements.
However, this theory does not explain evidence of different rocks starting side by
side and moving at different rates and in disparate directions.
Moreover, the physics calculations do not fully support this theory as wind speeds
of hundreds of miles per hour would be needed to move some of the stones.