The unnamed woman told police she was walking her dog in Golden Gate Park last week when she spotted a boy annoying geese congregating there, and after scolding him, the boy's father appeared and pushed her to the ground where she struck her head.
Bleeding from the back of the head and with abrasions to her arms, she was helped to her car by the man, and later in the day was hospitalized with what were described as life-threatening injuries, police spokesman Gordon Shyy said.
The father told park employee John Steele the woman grabbed his son's neck to stop him from playing with the geese, and when he tried to get her away from the boy, she fell and struck her head.
"Nobody really saw it. I don't think there were any other witnesses but the guy, his kid and the lady," Steele said.
Police are seeking the boy's father, Shyy said.