Officials received a 911 call at about 4 p.m. Thursday. The CHP, Reach One helicopters, the Coast Guard and other emergency officials worked to rescue the girl from the ocean.
She was transported to Oakland Children's Hospital, where she was pronounced dead.
The park service says the child's father went into the water to try to save her and was taken to Petaluma Regional Hospital to be treated for hypothermia.
The child hasn't been identified by officials and there are no further details available at this time.