The Final Hour

At first I thought that my quest to get to Racetrack Playa in time to photograph the moving rocks in the golden light before sunset had failed.

In about five hours of driving to get here, I had managed to get a flat tire and then waste time walking around the wrong end of the dry lakebed searching for these rocks and tracks in vain, thinking the sun had already set.

Just as I was about to give up, I thought I'd drive to the south end and see what's there. As I approached I saw another SUV parked and what appeared to be people in the distance. Suddenly the meaning of the word "Playa" hit me and I realized that walking around the middle of a lake, you do not find a "Playa"!

What's more, whereas I thought I had lost the sun behind the mountains, it turns out that at the point where these rocks are there's actually a gap between the mountains. Not only does this gap allow the sun to shine longer than the northern end of the lake (excellent luck for me), but I believe it also contributes to the explanation behind how these rocks move.

In my hypothesis, this low gap in the mountains on the west side of the lake allows for the wind to rush through with great force. The mountains on the southern and southeastern side of the lake form a curve to the north that these winds can bend around and continue to blow at great speed. This, I believe is the force behind the motion.

The second part of the hypothesis is lubrication. Having stepped in a bit of a wet area on the western side of the lake, I noticed how incredibly soft and slippery it was. When this very porous surface receives just a slight bit of moisture, I believe the entire surface of the lakebed becomes incredibly slippery, thus allowing the force of the wind (mentioned above) to ever so slightly and gently push these rocks.

Finally, the bend of the eastern mountains to the north creates a kind of a "wind bowl" where the wind can swirl around, thus perhaps explaining why not all of the rocks move in the same direction (over time).

Special thanks to G. Dan Mitchell for posting this photo that first got my attention and his subsequent advice on getting here.

A truly magical place.

Racetrack Playa
Death Valley [National Park]
California