This mysterious and ghostly phenomenon occurs at Racetrack Playa, Death Valley which is a fitting location! The stones travel long distances without any human or animal help! It seems as if they just lift themselves up and scoot along, making a trail or groove in the rock surface as they travel. Scientists' best guess as to why this happens at present is that wind at the level of the stones causes them almost to hydroplane. Sometimes they turn left or right, and other times it looks like two stones are racing each other. They only move every three or four years and the grooves take some time to build up. Definitely a wonder of the world!