The crash happened around 6:15 am on northbound Highway 99 near Collier Road, just south of Delhi.
Investigators believe he drifted, hitting the center median and veering off the road. The car rolled 50 feet down an embankment.
Officers found the 23-year-old driver dead inside the vehicle. His name has not been released.
The CHP said he was not wearing a seat belt. Investigators are looking to what caused the crash.