The Sonoma County coroner's office has identified the victim as Maribel Medina, 19, a resident of the Olivehurst community in Yuba County.
The CHP received a call at about 1:40 a.m. reporting a car traveling south on Highway 101 that went off the roadway south of Todd Road near Rohnert Park, according to Officer Nicole Pacheco.
CHP officers could not immediately locate the silver 2010 Mazda M3 because it had gone through some bushes and trees, hitting a tree near a frontage road.
Four people were in the Mazda, Pacheco said, and officers have not yet confirmed whether Medina was driving the car.
The car's other three occupants, Alejandra Meza, 19 of Rohnert Park, and Alejandro Cano, 19, and Arnaldo Salazar, 20, both of Santa Rosa, were transferred to Santa Rosa Memorial Hospital with major injuries, Pacheco said.
The CHP is still investigating the crash. Officers do not yet know whether alcohol was a factor.