FOSTER, Calif. -- One motorist was killed and another severely injured Tuesday in a head-on collision on State Route 67 near San Vicente Reservoir.

The accident occurred about 2:30 p.m., when a northbound Oldsmobile 98 veered across a set of solid double yellow lines near Johnson Lake Road, according to the California Highway Patrol.

The car continued traveling against traffic in the southbound lane for about a quarter-mile, CHP public affairs Officer Brian Pennings said.

Several motorists were able to steer clear of the errant sedan before a Chevrolet Astro van crashed into it, despite the driver's efforts to brake and veer out of the way, Pennings said.

The driver, a 36-year-old Julian resident, was pronounced dead at the scene. Her name was withheld pending notification of her family.

The driver of the Oldsmobile, 51-year-old John Hallaway of Las Vegas, was airlifted to a trauma center for treatment of "major" injuries, Pennings said. Hallaway told emergency crews he'd apparently fallen asleep at the wheel just prior to the crash, the officer said.

There was no immediate evidence that either driver was under the influence of alcohol or drugs, and both apparently were wearing seat belts at the time of the accident, according to Pennings.

The roadway was closed in the area for about an hour to allow for investigations and cleanup.