The rockslide was reported to the California Highway Patrol at 4:41 a.m. Sunday near a tunnel where Las Virgenes Road becomes Malibu Canyon Road and crosses Piuma Road in Agoura Hills.
Caltrans ordered the road shut all the way to Pacific Coast Highway, according to the agency's post on X.
At 9:13 p.m., it was reported that the rocks and mud were completely cleared but northbound and southbound lanes would remain closed until about 3 p.m. Monday while a geologist makes sure the area is stable and to give the area time to dry.
City News Service contributed to this report.