Declining rock movement at Racetrack Playa, Death Valley National Park: An indicator of climate change?

•Summarizes documented trail formation events from the literature•Uses Monte Carlo formalism to establish significant decline in rate of events•Nearby meteorological records show decline in winds and in ice formation conditions

We have inspected Racetrack Playa at Death Valley over the last 7 years and have not observed major episodes of rock movement and trail generation. We compare this null observation with the literature record of the rock movement using a Monte Carlo method and find 4-to-1 odds that the rock movement probability has systematically declined. This statistically significant drop in movement rate may indicate a change in the probability of the required conditions for movement: we note decline in the occurrence of strong winds and in ice-forming cold in nearby weather records. Rock movement and trail formation may serve as an indicator of climate change.