Reese Witherspoon could probably still claim the title of America’s sweetheart, but Hollywood’s overachiever might be the more accurate moniker for the 38-year-old actress these days.

Sitting amid the wilderness above Beverly Hills, Witherspoon talks about finding ‘the most true honest expression of who I really am’ in her new film ‘Wild,’ opening this week in U.S. theaters.

Stripped down and raw, critics are calling it her strongest role in years and it is largely of her own making, for she bought the film rights to the best-selling memoir from Cheryl Strayed, a grieving, wayward young woman who hikes over 1,000 miles (1,600 km) in a solo quest to heal.

It was the kind of role, she says, that was scarce when she founded her production company three years ago: strong leading roles for women, great parts that show complex characters. Witherspoon won the Best Actress Oscar in 2006 for her role as June Carter in ‘Walk the Line,’ but had not matched that success since. ‘You know, it wasn’t about the studios not giving me what I wanted,’ Witherspoon said in an interview. ‘You can’t expect people to develop projects that quintessentially capture what you want to say in film. If you want something done right, you do it yourself.’ After ‘Wild’ and their recent box office hit ‘Gone Girl,’ Witherspoon and producing partner Bruna Papandrea have 16 more projects in the works.

‘We have a project pretty much at every studio now,’ she said. Moviegoers will see a different Reese in ‘Wild,’ a Fox Searchlight film directed by Jean-Marc Vallee. Cheryl is grimy and bruised on the trail, and in flashbacks she mourns her dead mother Bobbi (played by Laura Dern), shoots up heroin and has rough sex with strangers, naked.

‘Audiences that saw me doing movies years ago have changed,’ said Witherspoon. ‘They have dealt with grief and loss and divorce and having children. You know your audience evolves and you have to evolve as well.’ Indeed, Strayed has found she has quite a bit in common with Witherspoon, the only person in Hollywood to whom she sent her book.

‘Sometimes people will decide that I have written this book about my wild behavior in my twenties and Reese is America’s sweetheart and they want to put us in opposition to each other,’ Strayed said. ‘And we laugh about that.’