The collapse of a portion of U.S. 101 at a road-repair site between Ukiah and Willits has closed part of the major north-south artery at least through the weekend, the California Highway Patrol said Friday.
"We can't say when it will reopen," a CHP dispatcher said, describing the "slip-out" area as "volatile."
The detour for cars, which is costing travelers an extra three hours, runs along California 1. Truckers are being asked to use Interstate 5.
The roadway collapse occurred Thursday south of Willits, where a contractor for the state Department of Transportation has been attempting repairs since November, said Allen Wrenn, Caltrans district director.