Photo by Tim Aston
What is happening here is quite simple, and the answer is not in electromagnetics or vibrations in the earth, as many assume. These rocks lay in a dry lake bed, which is hard like a brick. In this area of California, they are famous for flash floods, as the water drains off the mountains onto the flat lake bed, it travels quickly, the ground soaks up very little of the water but it does soften a bit. As the water accumulates on the floor it travels down a slight slope taking anything with it, as the soil softens these rocks get pushed down, away from the surrounding mountains leaving an indented trail which otherwise it could not. Simple, yes, so why the mystery? They have taken time laps photography many times of these rocks, sometimes for weeks and get nothing, nobody ever wants to leave their expensive camera equipment in a violent storm for days, thus a capture of this strange effect has not been witnessed as of yet.