Highway 1 in the Big Sur region has been shut down after part of the roadway crumbled into the Pacific Ocean, according to Caltrans officials.
The highway will remain closed to through traffic because of the washout near Big Creek Bridge, the agency said.
Caltrans crews began assessing the damage at daylight Friday and would follow that with cleanup and repairs.
There was no estimate on when the popular driving route would reopen, the California Department of Transportation said.
Central coast rainfall topped 15 inches (38.1 centimeters) when the storm stalled there at midweek, triggering mud flows that damaged about two dozen homes. Firefighters used earth-moving equipment Thursday to rescue a horse and pony from deep mud near Salinas in Monterey County.
On Friday, Gov. Gavin Newsom issued an emergency proclamation for Monterey and San Luis Obispo counties because of the storms that in addition to damaging Highway 1 forced thousands to evacuate.