McClure was last seen in Seattle, Washington on November 2, 1978. She, her boyfriend and some friends went to the Fandango Disco, which was inside the Sir Loin Inn at the Lake Forest Park Shopping Center, and met other friends there.

McClure had an argument with her boyfriend and decided to walk home, although her friends offered to give her a ride. Her residence was five miles away, in the 1500 block of northeast 89th Street. Her friends caught up with her walking in the 16500 block of Bothell Way northwest, about half a mile from the disco, and again they offered her a ride, but she refused to get in the car. She never arrived home and has never been heard from again.

McClure's roommate reported her missing the next day. At the time of her disappearance, she didn't have any credit cards and had less than a dollar in her purse. On November 8, her driver's license was found near the intersection of Interstate 5 and Interstate 405. This is about ten miles from where she was last seen. No other clues were located, however.

Police have stated they think she was abducted near Sheridan Beach. Her loved ones do not believe she would have abandoned her daughter; she disappeared ten days before the child's second birthday. Her now-grown daughter thinks she was abducted by someone she knew.