Sean Dungan (3)

Get them tree-huggers: Clausen, above, turned his obsession with ecoterrorism into a personal jihad against Earth First! Bottom left: EF! activists saving redwoods in 1990; right: eco-furor at the November 1999 anti-WTO demonstration/riot in Seattle.

"Do you eat meat?" he demands.

As long as it's medium rare, I tell him.

"Ah-huh. And what kind of beer do you drink?"

The cheap kind, I say. This goes over well. He agrees to pick me up in a couple of weeks at the airport in Redding, California, which is about as close as he'll come to disclosing where he lives.

Before I meet him, I track down a copy of Walking on the Edge, Clausen's self-published 1994 memoir. Spanning 1986 to 1993, the book details his struggle to become an undercover police informant on small-time drug deals in rural Montana. The author is referred to as "Barry," à la "Mailer" in Armies of the Night, but there the resemblance ends.

Plot point No. 1: Barry, a navy veteran and former railroad engineer, hires on with a computer company in Montana only to discover that the outfit is a cocaine smuggling front. "Talk about being in the wrong place at the wrong time!" exclaims our author. Plot point No. 2: Barry contacts the state attorney general's office and offers his services as an undercover source. The cops are impressed by his ability to chat up the local riffraff. "Hell," one agent tells him, "you could teach some of the regulars a thing or two." Barry thrives on the shadow work and helps break up a marijuana-selling ring. Plot point No. 3: When the market for amateur narcs dries up, Barry hires on as a seasonal trail worker for the U.S. Forest Service and meets Bruce Vincent, owner of a small family-run logging operation in northwest Montana. Vincent believes that his dump trucks and backhoes have been vandalized by radical environmentalists. "If these radicals are doing this kind of damage," asks a perplexed Barry, "how come they aren't in jail?" Aha! Which leads to Plot Point No. 4: After he drops hints about his investigative acumen, a group of loggers hires Barry to infiltrate Earth First!. He trades in his Trans Am for a beater truck, pulls on his scruffiest clothes, and learns the finer points of tree-sitting. But after attending Earth First! rallies and actions for nearly a year, Clausen's information leads to no arrests. Alas, the book ends with a whimper: The FBI stops returning his phone calls, the loggers cancel his contract. "Barry," writes Barry, "was disappointed, discouraged, disillusioned, and disgusted."

As a self-portrait, it's a bit thin. And getting Clausen to fill in the gaps takes time. Born in 1942, young Barry spent his childhood running an old skiff down the Fraser River in Vancouver, British Columbia, catching salmon and selling them at his grandfather's boat-repair shop. The Huck Finn days ended at 12 when his folks split up and he moved with his mother to Seattle. He left high school to join the U.S. Navy, where he learned how to fuel carrier jets and bust a little ass on shore patrol. After a six-year hitch, just as Vietnam was heating up in the mid-1960s, he punched out and took a job running freight on the Burlington Northern line from the Rockies to the Pacific. His railroad job kept him occupied for 15 years or so. But by the early eighties he'd decamped to Livingston, Montana, and started doing odd jobs for a small gang of Hollywood expats, among others, who had washed up in Big Sky Country. As Barry tells it, he ran into Peter Fonda at the grocery store, they hit it off, Fonda invited him to a party where he met Jeff Bridges, and the next thing he knew he was caretaking on Bridges's ranch and earning side money hauling Tom McGuane's cutting horses to Texas. (Reached in Montana, McGuane confirmed that Clausen had done some work for him but said he hadn't seen him in more than a decade.) After that Barry hired on with a startup computer company only to discover...well, that's where we came in.

At the Redding airport, Clausen isn't hard to spot. Wearing a stonewashed denim jacket and sporting a wispy tuft of thinning black hair, he looks like a shady character who just stepped out of a Coen Brothers movie. I find him standing next to a shrine to local athletes who done good. "Huh," he says, indicating a photo of a former U.S. Ski Team member. "Knew that guy."

Did you ski with him? I ask. He looks me straight on, which is slightly unnerving because his thick glasses give him egg-yolk-size orbs. "Yeah," he says. "Way back when."

We hop into a van, which may or may not be his, about which he'd rather I didn't reveal make, model, color, or plate, and which he later claims is equipped with sensitive remote recording equipment. He tells me about a conversation he had earlier that morning with a contact at the FBI. "I told him you only got two problems over there," Clausen says. "Janet Reno and Louis Freeh. And he says to me, 'Well, you got one out of two right.' Tells me Freeh's not the problem."

Not the most shattering insight in the world, but it's Barry's way of saying I shoot the shit with G-men. He's got my attention.

Who told you this? I ask.

"A guy I know at the FBI."

Yeah, but at what office?

"Oh, he's just a contact. He helps me out, I help him."

Hmm. OK.