PORTLAND, Ore. (KOIN) – It’s a 50-year mystery that’s left investigators stumped. On November 24, 1971, a man who called himself Dan Cooper bought a one-way ticket from Portland to Seattle. 

He soon became the most infamous skyjacker in U.S. history. 

And now, Netflix is about to release a documentary on him. 

The documentary “D.B. Cooper: Where are You?!” dives into the unsolved case and theories about where or who D.B. Cooper might be – if he’s still alive, that is. 

During the flight to Seattle, Cooper slipped a flight attendant a note and claimed to have a bomb in a brief case. Once the jet landed in Seattle, Cooper exchanged the passengers for $200,000 and four parachutes. Then, he demanded to be flown to Mexico. 

When the plane took off, Cooper and his bag full of money parachuted out and vanished somewhere in Southwest Washington. 

An extensive search was concentrated around the town of Ariel and Lake Merwin, with the command post in Woodland. Soldiers from Fort Lewis scoured the remote terrain but nothing was found. 

Nearly everything the FBI has on D.B. Cooper fits into a cardboard box, including the tie where the FBI found his DNA. The evidence is mostly what Cooper left on the plane. 

In 1980, on the banks of the Columbia River west of downtown Vancouver, an 8-year-old boy named Brian Ingram found some of DB Cooper’s cash. It totaled $5,800, but the rest was never found. 

Investigators used serial numbers from the bills Ingram found and traced them to Cooper’s ransom. 

No other trace of D.B. Cooper has ever turned up

The FBI believes Cooper’s jump killed him and in 2016 declared it was no longer actively investigating the skyjacking. 

Dan Cooper came to be known as D.B. Cooper from a reporter who received a tip about the 1971 skyjacking. The reporter misheard the name and wrote a story naming D.B. Cooper as the suspect. The story went around the world and the wrong name stuck to the man responsible for the country’s only unsolved skyjacking. 

The trailer for the Netflix documentary of D.B. Cooper includes shots from around Portland. The documentary will be released on July 13.