The driver was transported to Santa Paul hospital with minor injuries, a representative for SPFD said.
Ford, 75, was driving along California State Route 126 around noon on November 19 when he saw a gray vehicle swerve off the road into an embankment, TMZ reported.
Photos of Ford talking to first responders at the scene began surfacing online.
TMZ reports that eyewitnesses saw Harrison driving behind the stranger when she lost control of her vehicle and wound up crashing into an embankment right off the freeway.
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They worked to pull a woman safely from the vehicle while waiting for paramedics to arrive.
Senior Officer Matt Alonzo says Ford and the friend came to the driver's aid and acted as good Samaritans. The California Highway Patrol is now investigating the incident.
The actor - who is known for his fearless, heroic roles in movies like Star Wars and Indiana Jones - did not hesitate to rush to the woman's side. Ford, known as an avid pilot, had reportedly been at the airport earlier in the day, according to the Hollywood Reporter. Ford and others managed to get the unidentified driver out of the vehicle.