Cierley was last seen sometime during July 1998 when his nephew, John Henry Shipman, helped him move out of his Prineville, Oregon apartment. Shipman later told people that Cierley was traveling around the country in a motor home. He has never been heard from again.

Shipman is the son of of Frances Brewster, who was reported missing by one of her other children in May 2001. She was last seen in October 1999 and was living with Shipman at the time of her disappearance. Shipman told authorities that Brewster was traveling with Cierley, whose now-deceased wife was Brewster's sister.

Police discovered that Shipman was cashing both Brewster and Cierley's Social Security benefit checks after they disappeared. When they tried to arrest him on some unrelated domestic violence charges in September 2001, he killed himself with a shotgun. Federal indictments related to the check-cashing were pending against him when he died. Although Shipman never admitted to involvement in his mother and uncle's disappearances, authorities believe he murdered them both and buried their bodies somewhere in central Oregon.

Shipman and Cierley have never been located. Foul play is suspected in their cases due to the circumstances involved.