Two Santa Rosa men, acquaintances and both believed to be drunk, crashed into each other while driving on the grounds of the Sonoma Raceway, the CHP reported Monday.
Both men were arrested on suspicion of drunken driving, and one suffered major injuries in the Saturday accident.
Austin Fowler, 27, had been riding on a four-wheeler and Andy Bruno, 31, was in a Ford F-350 pickup.
Late Saturday afternoon they were at an event at the raceway.
Bruno was called to the raceway pits to bring some parts and was headed down the hill, CHP Officer Garrett Ray reported. Fowler, on a 2006 Kawasaki Quad, was headed up the hill.
As they approached each other the two men tried to maneuver away but instead turned in the same direction. When a collision was imminent, Fowler jumped from the quad but was struck by the truck, Ray said.
Fowler was taken to Queen of the Valley Hospital in Napa with major injuries, then transferred to Santa Rosa Memorial Hospital.
Bruno was taken to the Sonoma County Jail. Fowler was arrested and released for medical care.