updated 10/19/2013 AT 2:00 PM ET
•originally published 10/19/2013 AT 3:00 PM ET
It looks as if Reese Witherspoon is ready for the journey of her life.
The actress posted a pic of herself on WhoSay on Friday that showed her weighted down with a heavy backpack on the set of her new movie, Wild.
“So excited to play @cherylstrayed in a movie!” she said.
The movie, which Witherspoon is also producing, is based on the 2012 best-seller by Strayed and tells the story of her 1,100-mile hike on the Pacific Coast Trail.
The memoir chronicled inexperienced hiker Strayed’s journey of self-discovery on the trek.
The author, who has been on location in Oregon with Witherspoon and the film’s crew, shared the pic on her Facebook page and said, “It’s an extraordinary experience to see Reese Witherspoon dressed in the clothes I wore on the trail, her hair the same style and color as mine then, with my beloved/loathed Monster on her back packed just the way I packed it. I’m humbled and awed and so excited for you to see the movie!”
Watch Strayed talk about Wild and her transformative experience here.
Let’s start off the movie award season! Watch PEOPLE.com’s exclusive live-streaming show with interviews from the red carpet of the Hollywood Film Awards on Monday, Oct. 21, starting at 9 p.m. ET.