It happened at Road 60 near Avenue 308 in Tulare County just after 7:30 a.m. The 32-year-old mother and six-year-old daughter were the only two people inside the vehicle when an oncoming freight train struck the car.
The woman died at the scene. The girl was airlifted to Community Regional Medical Center with moderate injuries.
The California Highway Patrol says the two were not wearing seatbelts at the time of the crash.
Their identities have not been released.