A California Highway Patrol officer investigates a fatal crash that occurred on Highway 20 between Saratoga Springs and Witter Springs roads west of Upper Lake, Calif., on Tuesday, February 16, 2010. Photo by Elizabeth Larson.

The collision occurred at around 8 p.m. on a curve on Highway 20 between Saratoga Springs and Witter Springs roads.

California Highway Patrol Officer Kevin Domby said a passenger vehicle traveling westbound behind a big rig attempted to pass the truck and collided head-on with a car traveling eastbound.

The driver in the eastbound vehicle died at the scene, while the driver believed to be the cause of the crash had to be extricated, Domby said. The big rig driver was badly shaken but otherwise unhurt.

The highway was shut down and traffic diverted onto Scotts Valley Road or turned back as numerous CHP, Lake County Sheriff's deputies and fire officials worked on scene.

An air ambulance landed at the Half Diamond Ranch a mile and a half to the east of the crash site, and Northshore Fire Battalion Chief Pat Brown transported medical personnel from the helicopter to the scene.

A Northshore Fire ambulance later transported the surviving vehicle driver back to the ranch and the helicopter landing zone.

Domby said the particulars of the incident were still being investigated. Names of those involved were not immediately released.

The inquiry continued late into the night, as CHP officers diagrammed and photographed the scene.

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