Cheryl Strayed wrote an autobiographical book called Wild: From Lost to Found on the Pacific Crest Trail. Apparently Reese Witherspoon liked it: she's the producer as well as the main character (she plays Strayed).
The movie starts on the trail, but much of it is in flashback: it's not always obvious what point in her life we're looking at, but it's also usually not too important. They're establishing relationships in her life, her mother's (Laura Dern) influence and death, and Strayed's self-destructive behaviour. And, ultimately, her decision to "hike back to the person my mother believed me to be."
The performances are good, and the story is interesting. But it manages to be very slow-paced despite a number of interesting things happening. And the cinematographer (Yves Belanger) requires a special dis-commendation: in a two hour movie, we spend 70-80 minutes on the Pacific Crest Trail. In that time, he didn't manage a single moment of breath-taking beauty. How can you do that? It looks nice, yes ... but it should look glorious with the scenery available to him.