The 28-year-old man was driving north on Highway 99 at about 11:50 pm when he began to turn onto the Highway 152 onramp.
Investigators said the driver made an unsafe turn and drifted off the road, colliding with a tree in the center divider.
The impact of the crash split the vehicle in half.
CHP officers say the man was not wearing his seatbelt properly. He was pronounced dead at the scene.
It's unclear if alcohol or drugs were factors in the crash. The cause of the crash is still under investigation.