The slide was reported Monday in the Plug Hat Butte area, closing the Harpers Corner Road between the monument headquarters in Dinosaur, Colo., and Moffat County Road 16, the National Park Service said in a news release.
NPS officials had no estimate for when the road would reopen. The slide includes boulders the size of automobiles.
The slide does not affect access to the Dinosaur Quarry area on the monument’s Utah side, the park service said.