Cheryl Strayed’s memoir, Wild: From Lost to Found on the Pacific Crest Trail proves she’s fearless: in life and in her writing. This is a woman who once wrote a personal essay about her heroin habit for Doubletake, and on the sexual infidelity that undermined her first marriage in The Sun. In Wild, Strayed chronicles her three-month solo 1995 hike along 1,100 miles of the Pacific Crest Trail.

Wild is a mesmerizing story of successes and failures, simple pleasures and excruciating pain. But this book isn’t just a travel memoir: it’s a no-holds-barred account of what inspired a novice hiker to undertake such a grueling journey in the first place. Using the chronological framework of the trek to examine her life up to that point (she was 26), Strayed explores the aftermath of her 45-year-old mother’s death from cancer four years earlier: drug addiction, promiscuity, and a failed marriage.

“I hiked the trail out of a place of real sorrow and emotional desperation,” she recalls. “Physically suffering was healing to me.”

It’s a story that Strayed wasn’t ready to tell until she had “composted that experience” over the years and better understood what she had learned and what she wanted to say about it. In the interim, she moved to Portland, Ore., from Minnesota, started a family, and wrote a novel, Torch (Houghton Mifflin, 2006), a semiautobiographical account that follows the death from cancer of a young wife and mother.

Torch was the book I had to write. I could not live until I got it out of my system,” she explains, recalling that completing the hike gave her the confidence to obtain an M.F.A. from Syracuse University in 2002 and to pursue her passion for writing.

Her grief over her mother’s death when she was 22 and the subsequent breakdown of her family is a subject that Strayed returns to again and again in all her work. It’s an obsession with her, she admits: mothers who die young will always be a major theme in her work, whether it’s fiction or nonfiction.

One of the most pivotal scenes in Wild, in fact, has nothing to do with the Pacific Crest Trail, but everything to do with her late mother. The scene takes place half a continent away, in a horse pasture in northern Minnesota. It was almost three years after Strayed’s mother’s death in 1991 and one year before the hike. It’s a powerful scene that wasn’t even in the synopsis of Wild sent to publishers that resulted in Knopf senior editor Robin Dresser making a six-figure pre-emptive offer for the book. But it’s a searing memory that Strayed, who says that she doesn’t outline before writing, felt compelled to include.

Writing takes one “into all the dark places,” she says, describing the evolution of Wild as starting out as one personal essay for a planned collection that expanded into a memoir because she finally felt that she had to tell the whole story of the hike, including its backstory. The writing process, she claims, was “like a river pulling you down, the current going faster and faster,” her words heading “straight for that scene,” midway through the book. Strayed wept with sorrow the entire time she wrote about it.

“I can’t even imagine this book without that scene,” Strayed says, her voice choked with emotion. Describing the incident as the “worst thing” she’s ever done in her life, she adds that writing about it afforded “some dignity, some healing power” to the memory.

Although Strayed moves easily between fiction and nonfiction writing, she’s returned to writing fiction. While she says that her next novel, a story about four women living together in a house in Portland, is “probably the most fictionalized fiction” she’s ever written, there’s no doubt it will be powerful. “I don’t know any other way to write,” Strayed says. “The writing I’m interested in goes for the jugular—it just does not hold anything back.”