Donna Irene Lemon was 20 and planning to become a Registered Nurse when she disappeared in early July 1973. She and a friend, Sherry Pierce, attended rodeo events on July 3 and 4 and had planned to go horseback riding on the afternoon of July 5; Donna never arrived. Her family and friend searched that night with no success.

On the morning of July 9 a man walking along the Snake River in Idaho Falls found a woman face down in grass. A Montana driver’s license and later dental records identified her as Donna. She had multiple stab wounds and a fatal slash to the throat. Donna’s green Mustang was located about a mile from the body; dried blood and scattered contents were noted inside. Investigators lifted fingerprints and a palm print from the vehicle and later identified a male DNA profile, but no match has been found and no charges were ever filed.

Detectives treated the killing as someone Donna likely knew and explored several leads, including transient workers, a man she had been seeing, and the briefly considered but ultimately excluded suspect David Meirhofer. The case remains unsolved. Does anyone who knew Donna or saw her in early July 1973 have information that could help?