Gregory Lee Mansfield was 39 when he disappeared on June 20, 1988, during a rafting trip on the Gulkana River in Alaska. Traveling with two companions from Paxson Lake, the party encountered rough water near Falls Canyon. Mansfield and one companion were running the rapids when he fell from the rubber raft at about 5:00 p.m. He was not wearing a life jacket and was swept downstream, went over an approximately four-foot waterfall, and was last seen being carried away by the river toward a logjam.

After stabilizing the raft and reaching camp, one companion searched the riverbank with no sign of Mansfield. The next evening a helicopter search with a contract pilot, an Alaska state trooper and a companion examined the river from the air; subsequent trooper searches also failed to locate him. He was described as about 5 feet 11 inches, 170 pounds, blond hair, blue eyes, wore glasses, had tattoos on both arms and was dressed in river gear with a blue U.S.S. Stark baseball cap. No trace or recovery has been reported.

Does anyone who was on or near the Gulkana River that weekend remember seeing Mansfield or anything that might explain what happened after he was swept downstream?