The moving rocks, also known as
sliding rocks or sailing stones, are a geological phenomenon found in Racetrack
Playa, a seasonally dry lake (a playa) located in the Panamint Mountains in
Death Valley National Park , California. The rocks move across the surface of
the playa, leaving long tracks behind them as they go, without human or animal
intervention. They have never been seen or filmed in motion.
Racetrack rocks only move once
every two or three years and most tracks last for just three or four years.
Rocks with rough bottoms leave straight striated tracks while those with smooth
bottoms wander. Most of the moving stones originate from an 850 foot (260 m)
high hillside made of dark dolomite on the south end of the playa, but some are
intrusive igneous rock from adjacent slopes. Tracks are often tens to hundreds
of feet (low to high tens of meters) long, a few to 12 inches (8 to 30 cm) wide,
and typically less than an inch (2.5 cm) deep.
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