Mark Ruwedel, who has long explored both the natural and human-altered landscape of the West, photographed Moving Rocks #8 on the dry lakebed named “The Racetrack” in Death Valley National Park, California. The site is famous for rocks that have left trails on the desert floor as they have moved across the landscape over time. Although space aliens have been offered as one explanation of the movement, those who study them attribute the movement to rare confluence of rain, ice, and wind.