A crash that shut down rural Highway 20 near Ukiah for hours Friday started with a pickup driver who crossed double yellow lines and smashed into an oncoming big rig, according to the CHP.
The 7:15 a.m. collision occurred at a bridge over the Russian River, in Redwood Valley, north of Ukiah.
The damaged rig leaked about 190 gallons of fuel, and a fire broke out, with flames spreading to the bridge.
The highway remained closed early Friday afternoon, while cleanup continued and a review was conducted of the bridge's structural integrity, said CHP Sgt. Lanika Lee-Escorpiso.
After the two vehicles collided, the semi-truck and trailer began to jackknife and sideswiped another vehicle.
Injuries were minor and no one was transported to a hospital.
What caused the driver to move into the opposite lane remained under investigation Friday.
Traffic was diverted to nearby roads.