Michalenko was last seen in Keif, North Dakota on November 9, 1968. She and a male friend went to a bar and stayed until midnight. Her friend said he dropped her off at her in Butte, North Dakota, at the home of her ex-husband and three children. She has never been heard from again.

Michalenko had a history of leaving town voluntarily for extended time periods. As a result, she was not reported missing until December 27, six weeks after she was last seen. Foul play is now suspected in her case, but it remains unsolved and few details are available.