The California Highway Patrol says it happened around 9 am when she was driving northbound on Highway 41 toward connector ramp to northbound Highway 99.
At some point, the woman lost control of her car and crashed into a guardrail. After the car hit the guardrail, it went airborne and hit a concrete pillar.
Authorities say the woman was killed in the crash.
Investigators say alcohol or drugs do not appear to be a factor and the woman was wearing a seatbelt at the time of the crash.
The road was closed for three hours for the investigation.
The identity of the woman has not been released.