Rocks of various heft – some weighing 600 pounds or more – leave trails that wiggle like snakes or form complete loops or even rectangles. The trails are cut sharply into the earth but no other tracks are visible.
Theories over the decades have included sporadic hurricane-force winds when the surface is covered with rain water, or rocks carried across the mud by small rafts of ice, or UFOs.
But until a scientist had an incredible stroke of luck that day last December, no one had scientifically verified the phenomenon. The findings were formally presented in the online scientific journal PLOS ONE.
Geologists have been studying the moving rocks since 1948. One reason the mystery endured is that the movements are episodic, often with no motion for periods of decades until a precise series of natural events occurs.