Mary Jean Fryar was doing paperwork in the office on a quiet day in 2004 when an assignment came in from HQ.

“Oh my God, you guys,” she said to her fellow FBI agents. “We got a D.B. Cooper lead!”

This did not provoke the response she expected. “They just looked at me,” she recalls. “They’d never heard of D.B. Cooper.”

Fryar realizes now she shouldn’t have been surprised. Her colleagues in the Santa Rosa, Calif., field office were all young agents. At the time, it had been 33 years since a polite, well-dressed man going by the name of Dan Cooper had taken over Northwest Orient Flight 305 out of Portland. The hijacker ultimately parachuted from the Boeing 727 with $200,000 in ransom, never to be seen again.

The man’s daring Thanksgiving Eve crime in 1971 remains the only unsolved skyjacking in U.S. history. It’s led to endless waves of articles, books and TV documentaries. Despite the ignorance of those young Santa Rosa FBI agents, the hijacking of Flight 305 has taken on the status of a beloved legend.

“It will never be solved,” Fryar says. “Which is sad.”

Then she adds: “Unless he confesses.”

The retired investigator is cheekily referring to the suspect she was directed to visit and interview that California day 15 years ago: a former smokejumper and World War II veteran named Sheridan Peterson.

***

Eric Ulis has been researching the famous skyjacking for years. And like many amateur Cooper sleuths before him, he believes he’s solved the mystery. The Phoenix entrepreneur, one of the creators of the defunct poker-playing TV show “High Stakes Hold ’Em,” says he’s “98 percent” convinced that Peterson is D.B. Cooper.

That’s why he was hacking through thick foliage on Bachelor Island, near Ridgefield, Wash., last weekend. He believes the FBI misidentified Cooper’s “jump zone” and so searched the wrong stretch of forest in the weeks and years after the high-profile crime. This small isle along the Columbia River, most of which is part of the Ridgefield National Wildlife Refuge, offers pristine woodlands that have been largely untouched by humans for decades. Ulis has analyzed wind speeds, “free fall” data and other information that led him to conclude the skyjacker likely came down here.

Eric Ulis on his way to Bachelor Island, where he believes D.B. Cooper landed nearly 50 years ago. (Douglas Perry/The Oregonian)

If he’s right, he says as he stands on Bachelor Island’s gritty beach, “the parachute is here. He wouldn’t have taken it with him. It’s here. I feel strongly something is here. We just have to find it.”

Ulis took a boat to the island, guided by one of the last remaining owners of private land there, to begin the process of “establishing how best to conduct a search.” He plans to come back with a group of volunteers -- and a drone sporting special equipment for long-distance metal detection.

Even if he does find D.B. Cooper’s parachute, it wouldn’t prove Sheridan Peterson is the skyjacker -- though it certainly would validate Ulis’ approach to the case and his interpretation of recently released FBI files. And he points out that Peterson’s self-published 2018 roman à clef, “The Idiot’s Frightful Laughter,” “makes references that fit the island, so it would go some way to showing he was the guy.”

To be sure, so-called “Cooperites” like Ulis have floated dozens of suspects over the years. Most of them obviously are not D.B. Cooper.

But that does leave at least a few credible possibilities. Documentary filmmaker Tom Colbert spent close to a decade making the case that the Vietnam War veteran Robert Rackstraw is D.B. Cooper. (Rackstraw, retired and living in San Diego, threatened to bring a lawsuit against Colbert but never followed through.) More recently, an Army data analyst has homed in on a career railroad man named William J. Smith. (Put a photo of the late Smith next to the famous “Wanted” sketch of the skyjacker, and you’ll be certain you’re looking at the same person.)

Then there’s Ulis’ candidate. Sheridan Peterson, now in his nineties and living in a California retirement community, is apparently one of the few suspects whose DNA the FBI has compared to genetic material found on the skyjacker’s discarded clip-on tie. It’s possible none of the useable DNA remaining on the tie is related to the skyjacker, yet while the FBI has publicly stated that there was no match for suspects such as Duane Weber and Lynne Doyle Cooper, it has said nothing about Peterson’s sample.

Bachelor Island (Douglas Perry, The Oregonian)

Despite this, Sheridan Peterson has mostly flown under the radar even of Cooper obsessives. He isn’t mentioned at all in Geoffrey Gray’s well-received 2011 book “Skyjack: The Hunt for D.B. Cooper,” a compendium of the case’s enduring popularity, weirdness and many suspects. He’s rarely discussed on the ever-active online forums devoted to the Cooper case.

Peterson’s low profile baffles Ulis, and the Arizona man has repeatedly come to the Northwest to try to change that. Last November he organized a D.B. Cooper Conference in Portland, the city where the skyjacker’s famous journey began and where fascination about him continues. (The collegiate summer baseball team the Portland Pickles this month held a “D.B. Cooper Night,” where they asked “all fans to come forward with any info related to the infamous hijacking of a Boeing 727.”)

Ulis is taking advantage of the ongoing local interest. On June 29-30, he will conduct a D.B. Cooper Boat Tour, taking the Cooper-curious out to Tena Bar, the Columbia River sandbar where more than $5,000 from the Cooper ransom was found in 1980. He says the sandbar’s location links up perfectly with the skyjacker coming down on Bachelor Island.

***

“D as in dog or B as in boy?” the reporter asked his source. The phone line crackled and popped, and he pressed the handset hard against his ear.

“That’s right,” came the response.

And so, on the stormy Portland night of Nov. 24, 1971, “D. Cooper” became “D.B. Cooper.”

Ever since, the incorrect initials have been associated with the skyjacker. The mix-up with the name -- at that time a customer didn’t have to show I.D. to buy a plane ticket -- proved to be the first of many problems that would dog the case over the years. Most significantly, the FBI lost key physical evidence -- cigarette butts the hijacker left behind -- and couldn’t find complete fingerprints on the plane.

Whatever difficulties the FBI had early on in the investigation, agents zeroed in on Sheridan Peterson soon after the skyjacking. He simply made sense as a suspect. Peterson served in the U.S. Marine Corps. He worked as a technical editor at aerospace company Boeing in Seattle -- and as a refugee adviser in Southeast Asia during the Vietnam War. Most noteworthy of all, he was an experienced skydiver prone to quirky risk-taking, such as “experimenting with homemade bat wings.”

The FBI reportedly showed up at his ex-wife’s workplace shortly after the skyjacking and asked her if Peterson could be D.B. Cooper. Her response: “Yes, that sounded like something he’d do.”

Like his former spouse, Peterson wasn’t surprised by the FBI’s interest in him.

FBI personnel scour a beach on the Columbia River in 1980 after several thousand dollars of the hijacking money was found in the area days earlier. (AP Photo/Reid Blackburn)AP -WR

“Actually, the FBI had good reason to suspect me,” he wrote in a 2007 issue of Smokejumper, an obscure magazine published by the National Smokejumper Association. “Friends and associates agreed that I was without a doubt D.B. Cooper. There were too many circumstances involved for it to be a coincidence.”

He then listed some of those “circumstances”:

“At the time of the heist, I was 44 years old. That was the approximate age Cooper was assumed to have been, and I closely resembled sketches of the hijacker. But what was even more incriminating was the photo of me simulating a skydiving maneuver for Boeing’s news sheet. I was wearing a suit and tie -- the same sort of garb Cooper had worn, right down to the Oxford loafers. It was noted that skydivers don’t ordinarily dress so formally.”

These are all good reasons why the average person on the street might conclude Sheridan Peterson is D.B. Cooper. It is not enough for federal investigators looking to build a case for trial. The FBI moved on to other suspects.

Yet the bureau couldn’t completely quit Peterson. For some reason the FBI decided to send Fryar out to knock on his door three decades after the hijacking, when he was 77 years old. Fryar says she has no idea why it took the bureau so long to decide it should interview Peterson. She and another agent talked to him at his apartment, took a swab for DNA, and sent a report and the genetic sample off to Washington, D.C. That was the first and last thing Fryar had to do with the case. She never even heard whether the DNA matched.

“He was a charming guy,” she says of Peterson. “He had a lot of knowledge about the jump from the plane, because he’d been a smokejumper. And he was clearly interested in the case.”

He also seemed interested in being a suspect. “I think he gets a kick out of it, the attention,” Fryar adds.

During his interview with the FBI agents, Peterson expounded on the case in surprising detail -- including that one of the parachutes the skyjacker had been given was a pilot’s emergency rig, a detail the bureau still held close to its vest at the time. He also insisted he wasn’t D.B. Cooper. He claimed he was in Nepal on Nov. 24, 1971. He said he was living in a mud hut near the base of Annapurna.

A couple of years ago, Eric Ulis talked to Peterson on the phone and exchanged a few emails with him. (Peterson has not responded to calls from The Oregonian.) He did not confess to Ulis, but, as he did during his FBI interview, he proved knowledgeable about all things Cooper -- and offered a possible motive.

“He told me he was radicalized while in Vietnam [assisting refugees],” Ulis says. “What he describes as atrocities by U.S. soldiers radicalized him. I think he just snapped. He found himself out of a job and didn’t feel he owed American society anything.”

Mary Jean Fryar, for her part, says she “loves [Ulis’] passion” for the case. And she admits it’s possible he’s on the right track.

When Fryar left Sheridan Peterson’s apartment that day in 2004, she found herself grinning. She turned to her fellow agent.

“That might have been D.B. Cooper,” she said as they stood outside Peterson’s home. “But we’ll probably never know.”

-- Douglas Perry

@douglasmperry

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