At the annual Fox Searchlight Pictures holiday party last night, she appeared, all smiles, in a bright red dress, looking very chic, a far cry from how we see her as Cheryl in much of “Wild,” as she tries to prove that she can do something major to come to terms with herself and need for an independent feat. Loaded with a back pack that would weigh down a sturdier figure, Cheryl is determined to walk 1000 miles from California to Oregon, making her arduous way along the Pacific Crest National Scenic Trail.

Even making the movie must have been trying, let alone what such a real ordeal would have been. What makes the film, directed by Jean-Marc Vallée from a screenplay by Nick Hornby, especially interesting is its split-level approach. On the one hand we get the portrait on Cheryl on the march over tough, sometimes mountainous terrain. But there are also flashbacks into her life that show where she has been coming from and the issues that take the toll on her and lead to her deciding to do what she feels she must in the way of personal achievement.

Her experiences include the close relationship with her mother Bobbi (an affecting Laura Dern) and coming to terms with Bobbi’s death from cancer, a broken marriage and a degrading period of sleeping around destructively. At times the flashbacks seem invasive, but nonetheless, they add up to what makes the film more than a survival test but a revelation of one woman’s odyssey through life. On the trail, she meets various characters who add drama and sometimes congeniality to her trek.