The 60-year-old Upland woman, who's name has not been released, has broken bones and is expected to recover, said Lt. Shelly Vanderveen of the Claremont Police Department.
A 3-year-old girl from Fontana was injured in the same crash but police had no update on her condition Sunday morning, police said.
The child complained of pain to her head after the crash, Vanderveen said.
The head-on crash occurred about 11:30 a.m. Saturday at Baseline Road and Padua Avenue and involved a car and a sport utility vehicle.
Claremont police and Los Angeles County Fire Department paramedics were called to the scene where they found the woman, the only occupant of the car, injured and trapped in her car.
The girl was in the front passenger seat of the SUV.
The woman was flown to Los Angeles County-USC Medical Center and the girl was taken to Pomona Valley Hospital Medical Center, police said.
A youth and an adult in the SUV did not require hospitalization, police said.
Anyone who may have witnessed the crash, which is still under investigation,is asked to call the Claremont Police Department at 909-399-5411