Bodega Bay fire Capt. Jason Downing said the woman's vehicle went down a 75-foot embankment and landed on its side in the surf at Gleason's Beach in Bodega Bay south of Wright's Beach.
The woman was extricated from her vehicle and flown by the Sonoma County Sheriff's Department's helicopter to Santa Rosa Memorial Hospital after the 2 p.m. accident, Downing said.
The injured woman was the only one in the vehicle, Downing said. Her name was not immediately available.
The U.S. Coast Guard, Monte Rio Fire Department, California Highway Patrol and Bodega Bay Fire Department responded to the accident, Downing said.