Investigators say alcohol did not play a roll in the crash and do not believe the weather was a factor.
The CHP reports a black Nissan Murano was driving westbound on Highway 12 when the driver crossed over the double yellow lines to pass other cars and lost control of her car. An 83-year-old man in a red minivan tried to swerve out of the way, but ultimately struck the side of the SUV.
The 27-year-old SUV driver and an 83-year-old woman in the minivan were pronounced dead at the scene.
The other passenger of the minivan, whom the CHP believes to be pregnant, was taken to a Stockton hospital with major injuries. The elderly driver sustained life-threatening injuries and was hospitalized.