FILE of a CHP patrol car.
Both southbound lanes on Highway 17 out of Los Gatos are blocked after boulders rolled onto cars, the California Highway Patrol says.
The incident began at around 1 p.m. just south of Redwood Estates and traffic officials say drivers should expect traffic to be backed up for hours.
Caltrans has been called onto the scene to try to break up the boulders.
No other information was immediately available.
