The dry lake beds found throughout Death Valley, called playas, are known for the mystery of its moving rocks. The large rocks, some buried several inches in the lake bed, have left a trail of their movement hundreds of feet long revealing the turns the rocks made. There are no footprints around the rocks to indicate human or animal involvement.  The mystery remained unsolved for years but was finally resolved. It was determined and actually caught on video, that during the winter months, on rare occasions, rain in the mountains would flood the flat playas in Death Valley with an inch or two of water. The playas’ muddy surface would become slippery as grease. At night when the temperature dropped and the winds blew, a thin skim of ice formed. The wind drove the inch-deep water and ice across the playas carrying the rocks with it, leaving the telltale grooves in the surface. Thus, the mystery was solved.