This 1971 artist's sketch provided by the FBI shows the …

AP Photo/FBI, File | published: August 3, 2011

This 1971 artist's sketch provided by the FBI shows the skyjacker known as "Dan Cooper," or "D.B. Cooper," made from the recollections of passengers and crew of a Northwest Orient Airlines jet he hijacked between Portland and Seattle on Nov. 24, 1971, Thanksgiving eve. Marla Cooper of Oklahoma City, who was 8 years old at the time of the hijacking, told ABC News in an interview broadcast Wednesday, Aug. 3, 2011 that she is certain her uncle Lynn Doyle Cooper leaped from a Northwest Orient plane not far from her grandmother's home in Sisters, Ore.