Jean-Marc Vallee is garnering a reputation for taking unflinching looks at America’s quiet, yet often noble, underbelly. But his Hollywood rep is growing just as fast as a director adept at getting celebrities to go downright unflattering. He recently did it with Matthew McConaughey, whose emaciated turn as real-life AIDS patient and activist Ron Woodroof won him a best actor Oscar (in addition to an editing nomination for Vallee). Now the helmer marches in Wild, the real story of Cheryl Strayed, played by Reese Witherspoon—a spiritually lost woman who trekked 1,100 miles along the Pacific Crest Trail to find herself and reverse her philandering, drug-abusing ways. The movie has found some awards season buzz, both for Witherspoon and Vallee, a Quebec filmmaker who began doing French-language films before making the transition Stateside. Vallee recently spoke about the project, the shoot, and getting Witherspoon to not break her neck on the trail, which she completed largely on her own, camera crew in tow.

So which came first, the script or Cheryl Strayed’s book?

The script. I was fortunate enough to be at the right place at the right time by the (Wild producers), who had seen a rough cut of Dallas Buyers Club. And they decided “Why don’t we come to Jean-Marc with it?” I read straight through the script, then got the book. I knew I had to make this film. Not only for the story, but for the colorful tools I could use as a director: the emotional material, the flashbacks, the voiceovers, the physical sets.

Tell me about that. What’s it like to shoot on a camping trip?

Incredible. When I first talked with Reese, listened to her talk about the book, the material, going out there, I knew she was ready to do what McConaughey did in Dallas Buyers Club. She wanted to get out of her comfort there. I trusted her totally and she trusted me, which took away some of the fear. Still, the landscape was a challenge. Reese wasn’t going to stop. And we had all of the camping gear: coats, sweaters, boots. She had t-shirts, shorts and shoes. We certainly weren’t going to complain.

Considering that’s clearly her on the trail and in the water, this movie redefines “happy accidents.” Were there any scenes particularly frightening, or that bring you the most pride?

Not one scene in particular. But she really went through hell; she’s really falling, getting bruised, struggling. But what’s fascinating is, mid-way through the film, we wanted to have a lot of wild shots across the vast landscape—just this little girl with a big backpack. That really is what the movie is about. It’s what gives the story its emotion.

Was there anything particularly tough for Reese out there?

One of the great things about the book is how honest it is, and there are parts about drug use. Reese wanted authenticity. But she had a hard time smoking a joint.

What was rehearsal like?

There really wasn’t rehearsal. We wanted to be as spontaneous as a real hike. We had a script, but I didn’t want to spend much time telling her what to do, where to go, this is the action, this is where we’ll be set up. What often happened is, I put her in the rough position—we really didn’t have marks—and we’d shoot her simply feeling out the scene. There’s a lot of that. So focus had to be quick and good. We had to move wherever she would, to give the camera a feeling of moving 360 degrees.

How does it feel to have the subject of your movie on set?

At first, I was nervous. Cheryl was going to be right there, seeing what we did to her book. But soon she became a soul sister and spiritual advisor. She was open about what she went through in her book, and I saw she loved that we were trying to do the same thing. She was very clear about this being our project, a story to tell our way. She recognized film is different from a book. But I’ll admit—it was touching to look over after a scene to see her smiling or wiping away a tear.

How in the world do you get Hollywood royalty to shirk their looks—on camera no less?

You know what’s funny? I learned that some actors, like Matthew and Reese, they’re eager to do it. Let’s be honest at where these people are in their lives. They have everything: health, good looks, amazing kids, great houses. What’s next? What could they possibly want when they have everything? They want to be taken out of their comfort zone. They want to be challenged. The key is being willing to challenge them.

Jean-Marc Vallee photographed by Mark Mann