The shutdown was in effect between Pacific Coast Highway and Grand View Drive, the CHP said.
No one was injured in the mudslide, which was reported shortly after 1:30 a.m. and left several motorists stranded. Vehicles were towed out of the goopy mud that smothered the roadway and was 3 feet deep in some spots.
TRAFFIC ADVISORY UPDATE IN TOPANGA. TOPANGA CANYON BLVD. IS BLOCKED IN BOTH DIRECTIONS FOR 24-48 HOURS FROM PCH TO GRAND VIEW DR. DUE TO A MUD SLIDE— CHP PIO - LA County (@CHPsouthern) March 15, 2018
Caltrans crews were using bulldozers and other heavy equipment to clear mud and debris along a 100-foot stretch of the roadway.
"I wish they had told us a little bit earlier that the road was closed. You drive 30 minutes up the canyon, and then they tell you. It's a little bit frustrating but then you get in the scheme of things in life, and it's not that big of a deal," said one driver.
For Topanga Canyon residents, trouble like this comes with the territory.
"When you live in an environment like that, you live with nature, you don't control nature, you don't even try," said Joseph Rosendo of the Topanga Canyon Chamber of Commerce.
The closure of the boulevard, designated as State Route 27, is expected to last for 24 to 48 hours, according to the Highway Patrol.