Joanna Robinson, 23, disappeared in the late summer of 1975 and was last seen in Oregon on or about August 9, 1975. Her remains were found more than a month later, on September 21, 1975, in a shallow grave near Derby Dam, an exit off Interstate 80 east of Reno, Nevada. The condition of the remains prevented a definitive cause of death, but investigators treated the case as a homicide.

When discovered she was wearing a gold turtleneck, blue jeans, tan slip-on shoes and had three rings. Her vehicle was later found abandoned in a Reno parking lot, prompting speculation she may have been abducted. A witness reported seeing a woman matching Robinson’s description driving south on U.S. 101 with a male passenger and said it appeared the woman was being forced to drive. The identity of that man, if he was present, is unknown and no arrests have been announced; the investigation has since gone cold.

Anyone with memories of Robinson, her movements in August 1975, or information about the man seen with her is asked to contact the Washoe County Sheriff’s Office.