Chamberlin was last seen at approximately 10:00 a.m. on February 23, 1978 at a hospital in the vicinity of 13th Avenue and Hilyard Street in Eugene, Oregon. She had given birth on February 13 and was released from the hospital, but her baby daughter remained hospitalized due to low birth weight. Chamberlin went to the hospital that morning to nurse her baby. She was told she could take the child home that day, and telephoned a female friend to tell her the good news. She has never been heard from again.

Chamberlin's vehicle was later found abandoned in the nearby parking lot of a Coca-Cola bottling factory. There was no sign of her at the scene. She was in the process of a divorce at the time of her disappearance and had left her husband. Her mother reported her missing. Chamberlin's case remains unsolved and the circumstances surrounding her disappearance are unclear.