Mystery of moving Death Valley rocks solved

DEATH VALLEY NATIONAL PARK, Calif. (KABC) -- On a dry, flat desert stretch in the middle of Death Valley, massive rocks moving across the desert floor have been puzzling visitors for decades.

The rocks are somehow moving across the desert floor, but how? There are no footprints or tire tracks, just long rock trails in the dirt.

Could it be strong winds? A hoax? Aliens? Scientists have been trying to solve the mystery of Racetrack Playa since at least the 1940s.

More recently, GPS markers were put into rocks and placed around the desert, as scientists waited two years for movement.

As one of the other researchers on this project said, probably the most boring experiment ever. True, until this year," said Jim Norris of Interwoof.

UCSD scientists actually videotaped the rocks moving. The culprit was ice.

Rains and snow in late November of last year formed a pond in one end of Racetrack Playa that froze over. When it thawed, winds pushed huge ice sheets around the pond, sometimes moving rocks along with them, some as far as 700 feet. When the pond dried up in February, there were tracks left in the mud.

It turns out, it doesn't take much ice to do the trick, only about the thickness of a windowpane.