Ronald Terry Curby, 40, was last seen leaving a party in Tulsa on June 19, 1981, intending to drive home to Bartlesville. He worked as a marketing manager for Applied Automation and had been with the company for 20 years. It was out of character for him to change plans without telling anyone.

Early the next morning an Applied Automation employee found Ronald’s locked car parked along U.S. Highway 75 a couple of miles south of the Washington–Tulsa County line. The vehicle appeared undisturbed and in working order. A wide, 10-square-mile search of the area turned up no evidence about his whereabouts.

A long-haul truck driver later reported seeing Ronald’s car at about 2:30–2:45 a.m., with a second vehicle parked behind it and two men getting into that second car. Investigators interviewed partygoers, some of whom took polygraphs, and tried further questioning of the trucker, including hypnosis, but no breakthrough developed. Ronald walked with a limp from childhood polio and often wore a leg brace, a detail his family hoped would help identification.

Does anyone who remembers that stretch of U.S. Highway 75 in June 1981 or who knew Ronald have information that could help explain what happened that night?