The racetrack valley within Death Valley is called Racetrack Playa, a dry lakebed with a very ﬁne clay surface. The term racetrack comes from the trails or tracks the lakebed’s rocks leave behind them when they “race”— that is, mysteriously slide along the ﬂoor of the lakebed. (Though the prevailing theory is that this movement is due to a combination of strong wind gusts and deceptively slick clay, so far no one’s managed to actually document a rock in motion.) In South Dakota, however, the designation racetrack valley has nothing to do with lakebeds or moving rocks. There, the feature is an oval valley of red shale and sandstone that rings the Black Hills. Sacred to the Lakota, this Racetrack Valley is the result of a great race run long ago by all the world’s creatures. On American maps, it shows up as Red Valley, just between the Black Hills and the Dakota Hogback to the east of the hills. Yet another Racetrack Valley can be found on the western slope of the Rocky Mountains in Granite County, Montana. There, the name comes from association with Racetrack Lake and Racetrack Creek, which in turn get their names from Indians who camped around the warm springs in the area for long enough periods of time that horse racing became a regular occurrence.