On Thanksgiving Eve, Nov. 24, 1971, a middle-aged man boarded a Boeing 727 in Portland enroute to Sea-Tac International Airport and sat alone. Unbeknownst to the flight crew and other passengers, they were about to witness one of the most curious crimes in U.S. history.

The Highline Historical Society has set up a display at SeaTac City Hall, 4800 S. 188th St., remembering the events of that day, and the man who committed the crimes of extortion and hijacking-D.B. Cooper.

The exhibit is scheduled to run through November.

The man of mystery was never caught, and his true identity never discovered. He boarded the plane in Portland, asked a flight attendant to have a seat next to him and handed her a note. The note demanded $200,000 in ransom and four parachutes.

The flight attendant, known as Ms. Schaffner, also says she saw a red cylinder in the one suitcase Cooper had, according to Nancy McKay, curator of the Highline Historical Society.

Schaffner passed the note along to the commander of the plane, Captain William Scott, while another flight attendant, Tina Mucklow, took a seat next to the "mystery man."

The display at SeaTac City Hall is located to the left of the lobby in two display cases. With newspaper clippings, facts, and artist renderings of Cooper the display gives what little information is available on the man and the case.

Capt. Scott, according to a document written by McKay based on information from a conference about the case, contacted officials in the Northwest who told him the money and parachutes would be available when the plane refueled at Sea-Tac.

The $200,000 was gathered together by several banks in the Seattle area.

"The airplane landed after about 1 hour and 40 minutes of circling," wrote McKay. "The plane's 36 other passengers, who were not aware of the hijacking, left the aircraft at Sea-Tac with Miss Schaffner and a third stewardess, Mrs. Alice Hancock."

As the plane was refueling, according to McKay, a courier arrived with the ransom-- all in 20-dollar bills, and the four parachutes. This person passed along these things to Mucklow.

The name of the courier is not noted in McKay's writings. However one local man did tell the Highline Times he was the courier. He did not return phone calls from the Highline Times seeking more information.

The man known as D.B. Cooper ordered the plane to fly to Mexico, but did not specified a route.

"The hijacker also demanded the crew open the plane's rear door and lower the stairwell after takeoff from Seattle," wrote McKay.

The hijacker was told the plane would be stopping to refuel in Reno. He then instructed Mucklow to close the curtains between first and coach classes.

The plane landed in Reno, and as Capt. Scott attempted to call the hijacker on the intercom it was realized there was no one in the back. "D.B. Cooper" had jumped from the plane.

The mystery began here. Alive or dead, the mystery man was ever found. And over the years the only clues have been the occasional finding of some of the extorted money.