Donald Cary Ewalt was 22 when he was last seen in El Centro, California, in early September 1979. He reportedly left work in the company of three unidentified men and was never heard from again. Ewalt was 5 feet 9 inches tall, about 120 pounds, with black hair and hazel eyes.

Foul play is suspected and the case was later reclassified as endangered missing. The Texas Department of Public Safety has assisted because of potential leads linking the disappearance to other regions, but no significant breakthroughs have been reported and the case remains unsolved.

Anyone who saw Donald in El Centro in early September 1979 or who has information about the three men seen with him is asked to come forward.