The star of bubbly hits Legally Blonde and Sweet Home Alabama doesn't seem like the obvious choice to play a grieving, heroin-shooting, sexually promiscuous woman who treks 1,000-plus miles by herself across the American Northwest. But Reese Witherspoon was captivated by Cheryl Strayed's 2012 memoir, Wild, which details the author's grueling, transformative hike on the Pacific Crest Trail after the death of her mother. Optioning Strayed's book with her own money and developing the project independently, Witherspoon and director Jean-Marc Vallée worked from a script by novelist Nick Hornby (High Fidelity, About a Boy) during a tight 35 days on location in Oregon and California. ''It's the hardest film I've ever made on many different levels: emotionally, physically,'' Witherspoon says. ''Honestly, nothing prepares you for carrying a 40-pound backpack up and down mountains and snow.'' Given the Oscar buzz that Wild is generating, she could be adding another 8.5 pounds to that backpack in 2015.