Emergency crews responded around 12:30 p.m. to the Wildhorse Valley area of the park and found two women and a man trapped in a creek bed at the bottom of the ravine, according to Palo Alto Fire Department spokeswoman Barbara Cimino.
Cimino said one of the women, 75-year-old Julie Barney, had been walking with her friend, 91-year-old Bill Duncan, when Barney somehow tumbled about 50 feet into the creek bed.
Duncan then deliberately slid down the steep ravine to help her but the two could not get back up, according to Cimino.
Another hiker happened to hear them calling for help and looked down, then summoned help from 911 and slid down the ravine herself to make sure Bailey and Duncan were all right, Cimino said.
Emergency personnel used rescue harnesses to pull them from the ravine. All three declined medical treatment, according to Cimino.