Mildred Louise Butterworth Roche, 38, was last seen by her parents on May 31, 1976, at their farm in Eagle Lake, Minnesota. She and her husband, Ronald Roche, were leaving to drive back to their home in Fargo, North Dakota; that departure was the last time her family ever saw or heard from her. Mildred, known as Millie, had long brown hair, brown eyes and a mole on her right cheek, and she took prescription medication for a mild form of epilepsy.

Ronald later wrote that the couple had agreed to divorce and that Mildred left him on June 2, 1976. He told police she packed two suitcases, an overnight bag and between three and four thousand dollars in cash and traveler's checks, and he said she phoned him three times after leaving, the last call coming from Boston in August. Investigators never found evidence to support those calls or that she had been in Boston.

In 1996 police excavated the Fargo backyard but found nothing of interest. Ronald sold the car used for the trip less than a week after Mildred disappeared; he remarried in 1977 and died in 2018 without ever being charged. Foul play is suspected and the Fargo Police Department continues to investigate. If anyone knew Mildred, saw her after May 31, 1976, or has information about her movements, please come forward.