Emile Hirsch's grueling, rewarding shoot with idol Penn

HOLLYWOOD — Emile Hirsch woke up at the edge of his bed after weeks of filming "Into the Wild," shouting into what he thought was the Grand Canyon, convinced that director Sean Penn had abandoned him to test his endurance.

"Sean's really pushing me now," he thought. "How could they do this to me?"

Even after he registered the blank hotel-room walls around him, Hirsch wasn't sure what town he was in. The months-long shoot had taken them to locations from Mexico to Alaska. It was starting to wear on him.

But it wasn't like Penn didn't warn him. As Hirsch recalled it, Penn was visibly relieved when he accepted the part. "You're a good guy," Penn told him. "You've got a good head on your shoulders. ... I'd feel bad about what I was going to put you through if you were really tortured at the get-go."

"Into the Wild," which opens today, set a new threshold for Hirsch. He dropped a quarter of his body weight for the part of real-life adventurer Christopher McCandless, who in 1990 set out alone on a two-year cross-country trek, eventually heading for the Alaskan wilderness only to starve to death four months after he got there. Hirsch ran 20 miles a week. He canoed river rapids. He came face-to-fangs with a grizzly, take after take. He carried a 30-pound pack much of each day. Even in waist-deep snow. Macho stuff for an actor whose most daring on-screen challenge up to that point had been shaving his head for the skateboarding film "Lords of Dogtown."

But Hirsch said he was so pumped up while filming "Into the Wild" that the physical exhaustion, that he was working for one of his idols, that the role could launch him as a leading man, didn't really get to him. He just felt lucky.

"I believed in what I was doing so much that I was never really nervous in ways that I've been on other projects," he said. "I was always like, 'Wow. I can't believe [Penn] hired me.' "

Indeed, Penn had envisioned Leonardo DiCaprio in the part 10 years ago, when he first read the book. But by the time he got the movie rights, DiCaprio was too old for the role. Hirsch, however, was just the right age. "On the cusp of going from boy to man," Penn said.

"Into the Wild" and Hirsch, specifically, already have earned high praise and Oscar buzz coming out of the Toronto Film Festival.

Hirsch, 22, grew up in Los Angeles and Santa Fe, N.M., and started acting at age 8. By 14, he was regularly landing small parts on TV. His first film role was in 2002 in the lead of Jodie Foster's "The Dangerous Lives of Altar Boys."

To prepare for "Into the Wild," Hirsch pored over McCandless' tersely written journals looking for clues. He read some of McCandless' literary idols, like Henry David Thoreau and Jack London. He visited McCandless' parents and spent a few days with his sister. He also trained and dieted relentlessly.

McCandless grew up in an affluent home in Virginia. But after he graduated from Emory University, he gave away his savings to charity, abandoned his car, went by the name Alexander Supertramp and hitchhiked around the country and then up the coast to Alaska.

There, he spent more than 100 days living in an abandoned bus in the brush. When he ran out of food and decided to leave, McCandless found the river too swollen to pass. He mistakenly ate some wild plants that he soon realized inhibited his body from absorbing nutrition, and he died of starvation.

Creating that moment on film, when he knows his fate is sealed, was one of the toughest for Hirsch. "You know, this is your life," Penn told Hirsch. "I can't tell you what to do here. This is your life.' "

"Then he walked off," Hirsch said. "It was just an amazing moment. How can you tell someone how to react when you find out you're going to die like that? He wanted it to be so personal and real. He just gave it to me."