The Sliding Rocks of Racetrack Playa

It’s like a highschool physics question that was never intended to be more than hypothetically abstract brought to life at grand scale.

One of the most interesting mysteries of Death Valley National Park is the sliding rocks at Racetrack Playa (a playa is a dry lake bed). These rocks can be found on the floor of the playa with long trails behind them. Somehow these rocks slide across the playa, cutting a furrow in the sediment as they move.

Mind boggling. On the one hand, it seems wildly improbably that a combination of utter flatness, utter slipperiness, sufficient wind, and the presence of a few, isolated objects would come together just so to make the phenomenon possible. Especially if you accept that some of these rocks are 100s of pounds. On the other hand, if it does happen at racetrack playa, it seems improbable that the conditions are so exquisitely specific that they’ve never come together anywhere else.

And no one has ever seen it happening?