Details of Disappearance
Niki ran away from her home in Albany, Oregon on July 16, 1969. She was living with her grandparents at the time of her disappearance. They legally adopted her after her parents divorced; this was supposedly to ensure that Niki's father, who was allegedly abusive, wouldn't get custody of her.
Her mother, Nancy Mahaffey, remarried and moved to Pennsylvania, leaving Niki behind in Oregon; Niki began running away after that. For a time in 1966 and 1967, she stayed at Hillcrest, a juvenile correction facility.
Niki called family friends in September 1969, trying to get in touch with her grandparents. She said she was in New York, had a job and was all right. This was the last time her family heard from her. Her grandparents kept the same phone number for the rest of their lives and never changed the locks at their Albany home, in case she should come home or try to contact them.
Years later, Mahaffey found a letter, supposedly from Niki, at Niki's grandparents' house. The letter said Niki was living with "some people in a big old house" and that she "might come home someday but right now I have to do what’s right for me." Mahaffey doesn't think Niki actually wrote the letter, however; she thinks Niki's grandmother may have written it, to make herself feel better about Niki's disappearance.
Niki's grandparents and her father are all deceased, but her mother is still alive and hopes to locate her daughter. Her mother has remarried and changed her name multiple times since 1969; Mahaffey is her current family name, but she also went by the names Weakland and McFarlane.
Niki's Social Security number hasn't been used since her disappearance. Her case remains unsolved.