Mary was last seen by her 8-year-old son and 6 year old daughter when she visited them in school one day in 1965. She told her son she was going away for a while, but would be back. She then traveled to her sister, Kathleen Lindstrom's,(according to Kathleen) home in Muskegon where she left a photograph and disappeared.
Though she wasn't reported missing until August 2002, investigators discovered there is no record of Mary, public or private, since the mid-1960s; and there has been no activity on her social security number since that time. (Information retrieved from NamUs.gov)