PORTLAND, Ore. (KOIN) — Nearly 52 years ago, DB Cooper jumped from a plane near the Washington-Oregon border with $200,000, never to be seen again. The mystery of the dapper airline hijacker who boarded the plane in Portland on November 24, 1971 only grows as time goes on.

Though the FBI has officially closed their investigation, researcher Eric Ullis keeps searching for new clues. On Monday he conducted a ground search near Tena Bar, the spot along the Columbia River where a portion of the ransom was discovered in 1980.

On Tuesday Ullis embarked on an 11-mile trip re-enacting an escape route Cooper likely took if he survived the jump.

Sketches of D.B. Cooper (FBI) March 7, 2023.

But at this time, it’s not clear if Ullis found any new information.

No trace of DB Cooper has ever turned up — no parachute, briefcase, clothing or body. The FBI now believes Cooper’s jump killed him — whoever he really was.