Wanstreet was last seen on the property of Hickman's Family Farms near Salome Highway and 330th Avenue in Tonopah, Arizona sometime after 9:00 p.m. on December 5, 2009. Her boyfriend lived and worked there. He stated they got into an argument and Wanstreet left to walk ten miles to her own home, but she never arrived and has never been heard from again. According to Wanstreet's daughter, her boyfriend has a long criminal record and was released from prison not long before Wanstreet vanished. Her daughter stated she saw bruises on her mother's body and Wanstreet stated her boyfriend had thrown her against a car. He hasn't been named a suspect in her disappearance, however, and he allowed police to search his trailer at the ranch.

Wanstreet had a bout with breast cancer prior to her disappearance, and on the day before she went missing her doctor told her she was cured. Her case remains unsolved.