FRESNO, Calif. (KFSN) -- It happened at around 3 p.m. in the Clear Lake area, at the exit onto State Route 198.
CHP says a motorhome towing a Honda Odyssey failed to slow down at the exit and rolled down the embankment.
A woman passenger in the motorhome died during the crash.
The driver, 74-year-old Robert Littlejohn was transported to Community Regional Medical Center with major injuries.
Officers believe alcohol or drugs did not play a role in the accident.