Catherine Lynne Sjoberg, 17, was last seen in the early morning hours of June 5, 1974, after attending her Oconomowoc High School prom at the Concord House dance hall in Concord, Wisconsin. Around 3:00 a.m. she stepped outside after a heated argument with her boyfriend to get fresh air and never returned. She had planned to stay at a friend’s house that night; her mother did not realize she was missing until the next day.

At the time she disappeared Catherine was wearing a long light blue prom dress with white flowers, a corsage, and gold jewelry. Described as a happy, responsible teenager who was due to graduate and serve as maid of honor at a family wedding, she had no apparent reason to run away. Authorities later examined possible connections to other crimes, including the unsolved disappearances and murders of two teens from the same venue six years later, but no concrete link was established. Age-progressed images have been created and investigations have continued, yet Catherine has never been located.

Does anyone who attended the Concord House prom that night or who knew Catherine or her boyfriend have information that could help clarify what happened?