The road is closed in both directions between Sanborn and Redwood Gulch roads near Saratoga by debris flow, Caltrans said.
The driver ran from the crash, but was captured by officers.
A monthlong closure of a scenic mountain highway that began Monday is already throwing drivers and their navigation apps for a loop.
An unstable hillside and more storms in the forecast have kept the timeline cloudy for reopening the closed stretch of road.
The road was temporarily closed in both directions following the wreck.
The mudslide was reported at 9:35 a.m. Thursday on state Highway 9.