From PEOPLE Magazine Click to enlarge
Back when the producers of Men in Trees were looking to cast the role of Jack—the rugged biologist who heats up the Alaskan wilderness with a big-city transplant played by Anne Heche—the show's creator Jenny Bicks vividly remembers the moment James Tupper walked in the room. "He was wearing this bulky fisherman's sweater, and I was like, 'We're done,'" recalls Bicks. "He was the strong, silent type. When he smiles, his eyes twinkle. It's kind of hard to not fall in love with him."

Agreed. Once the ABC series started filming, Tupper quickly earned the on-set nickname "McTreemy" because of his burgeoning heartthrob status among viewers. Also, no one could deny the electricity that he and Heche were generating on the set.

"Anne and I have wonderful onscreen chemistry," says Tupper. "I'm happy that people like to watch us. It's a beautiful thing." Of course, they make a beautiful couple off-camera, too. In January Tupper and Heche were spotted getting cozy in a restaurant and on a plane from Vancouver (where Trees films) to L.A. Though Tupper would rather talk about Trees than his romance, he does say that he and Heche "really trusted each other almost right from the beginning ... I adore her, and I'm hopeful for the future."

Tupper also admits he and Heche grew close by leaning on each other as their respective marriages were coming to an end. Tupper, 41, separated from his writer wife, Kate, late last year ("We remain very good friends," he says). Meanwhile in January Heche, 37, announced her separation from her husband of five years, Coley Laffoon, 33, with whom she has a 5-year-old son, Homer. Tupper insists the two remained platonic pals until their marriages ended. "The line," he says, "was never crossed."

Tupper, a Nova Scotia native, is the third of five children of James, an elementary school principal, and Heather, a homemaker who died when Tupper was 6. "You can't not be changed by it," he says of her death, which came just days after she was diagnosed with acute leukemia. "There's a ghost. But I was left with a great father."

After college Tupper spent 15 years working in theater—while holding down day jobs as a carpenter, a refrigerator deliveryman and a busboy—before snagging small roles on shows like Gilmore Girls and CSI: NY and then landing his current gig as Trees' leading man. "Success is a complete surprise," he says. "All the friends and family who watched me struggle say the same thing: 'Wow—you earned it.'"

Of course, Tupper's still getting used to the attention that comes with success. "I'm just getting my head around the idea that when you walk down the street, people recognize you," he says.

And then there's the whole sex symbol thing. "I block it out," says the 6'1" Tupper, running a hand through his wavy, Patrick Dempsey-caliber mane. Still, Tupper isn't complaining. After all, he still remembers the days when earning a living meant "building things in the hot sun."

Though carpentry is no longer his vocation, the avid woodworker still blows off steam in the shop. Recent projects for friends include a 17-ft. desk and a new set of stairs. He's also big into bird-watching and cooking and claims to make a mean Baked Alaska. So does Tupper, who says he'd love to have children one day, see himself settling down and whipping up desserts for Heche on a full-time basis? "I'm not ready to rush into marriage," he says, but "I've never met anyone like her. There's something really comforting when you can truly connect with someone and be understood. Isn't that what we all want?"