A head-on crash involving a big rig and a Toyota pickup briefly closed Lakeville Highway south of Petaluma on Saturday afternoon.

The 2 p.m. crash near Ernie's Tin Bar resulted in major injuries to the driver of the pickup, who was transported by ambulance to Santa Rosa Memorial Hospital.

CHP Sgt. Chris Linehan said that according to witnesses, the eastbound Toyota drifted into the opposing lane of the big rig, which was hauling two empty trailers.

The pickup struck the left side of the big rig and spun around.

The names of the drivers had not been released by Saturday night.

Officers were able to restore one lane of traffic initially. By 3:20p.m., all lanes of Lakeville Highway were open.