Tammy Dawn Risenhoover was 19 when she vanished from Tulsa, Oklahoma, in the early months of 1984. The exact date of disappearance is not known. She was 5 feet 2 inches to 5 feet 3 inches, about 130 pounds, with dark brown hair, hazel eyes and a purplish-colored birthmark at the hairline on the back of her neck; she sometimes wore glasses.

Tammy had a history of epilepsy and was known to associate with a local motorcycle gang at the time she went missing. Law enforcement considers the circumstances suspicious and strongly suspects foul play. She was not officially reported missing until March 6, 1990, six years after she was last seen, a delay investigators say hindered early leads and evidence.

The case is cold and remains unsolved. If anyone knew Tammy, her associates, or has information from Tulsa in 1984 that could help, please share what is known with the investigators handling the case.