ST. LOUIS (AP) – For 50 years, an unsolved mystery in St. Louis centered around who piloted the small plane that flew through the legs of the newly-completed Gateway Arch in 1966.

A suburban St. Louis woman says it was her father. The 630-foot tall monument was newly completed when, on June 22, 1966, a small plane suddenly approached from the west, made a low pass and flew straight through the Arch legs. Tourists and a National Park Service guide could only look on in surprise.

The pilot zoomed away, never to be identified. Until now.

Donna Dorris, who is 75 and lives in Madison, Illinois, told the St. Louis Post-Dispatch that her father, Earl Bolin, was the pilot. She says the family has held onto his secret for five decades.