When author Andrea Lankford says that she put “a lot of blood, sweat, tears, and broken bones” into her new work of nonfiction, “Trail of the Lost,” she’s not speaking in metaphor.

While investigating a lead for the book, which details multiple searches for missing hikers on the West Coast’s Pacific Crest Trail, Lankford shattered her ankle while alone and in a remote stretch of the path. She trudged her way out of an area near the San Jacinto Peak over several days, and she still bears scars from the titanium bar and screws necessary to repair the damage to her body. If she didn’t have her extensive outdoors experience to guide her, she might have joined the list of those lost on the PCT during that trip.

“Nature’s beauty often brings me to tears,” Lankford writes in “Trail of the Lost.” “But every now and then, she can also scare the s— out of me.”

A National Park Service ranger for 12 years, much of her work in parks such as the Grand Canyon, Yosemite and Zion focused on law enforcement duties including criminal investigations, wilderness medicine and searches for lost hikers.

“I know that danger lurks out there,” Lankford said, noting that while many PCT hikers might “think they’re in Disneyland,” that for her, even now, “it feels more like Jurassic Park.”

“I dealt with tragedy and death and crisis and conflict,” Lankford continued, and when burnout came, it came hard. “There was a time whenever I would go visit a national park, even for fun, I’d start to feel anxiety. I would be at a trailhead and look at visitors and think, ‘Oh, no, something’s gonna happen to them. They’re not prepared.’ ”

Leaving the National Park Service for a career in nursing helped quell that anxiety. Time spent outdoors, including hiking the entire 2,190-mile Appalachian Trail, also took the edge off her worries. “It was very therapeutic for me to do something in nature for fun instead of for work,” she said.

There’s an argument to be made that “Trail of the Lost” is another attempt to heal from that trauma. Lankford says that the idea for the book began when she was asked to consult on an abortive true crime TV series about lost hikers. That led the California Sierra foothills resident to the case ofChris Sylvia, a hiker last seen on the PCT on Feb. 16, 2015, near the San Diego County enclave of Warner Springs. The 28-year-old’s profile — “unemployed, and living in a friend’s apartment” — brought up memories of Gabriel Parker, a hiker found dead at the Grand Canyon months after Lankford led a fruitless attempt to save him.

“Parker’s case taunted me like a critic,” Lankford writes in her book. She hoped that joining the search for Sylvia might help her put those regrets to rest, but instead, it led her to Cathy Tarr, the arguable heart of the book.

When she turned 52, Tarr quit her job at the corporate level of Walgreens, sold most of her stuff, and started the work to hike the full, 2,653-mile length of the PCT, which runs from the bottom of California to British Columbia. The demanding trail had transitioned from a hiking destination to one popular with the masses after the bestselling success ofCheryl Strayed’s2012 memoir “Wild,” about her hike along 1,100 miles of the trail. The2014 film adaptation, which starred Reese Witherspoon and garnered two Oscar nominations, brought even more hikers — many of them novices — to the PCT.

但塔尔不是注定的to join those throngs, at least not in the way she expected. A few weeks before she was due to start her long walk, Tarr was injured in a vehicle collision. As she recovered, she took to PCT-focused Facebook pages, where she heard about the disappearance ofKris Fowler, who was last seen near mile 2,294 of the trail on Oct. 12, 2016. Six months later, she learned about a second hiker,David O’Sullivan, who disappeared from the trail near Idyllwild (Riverside Country). As opposed to resuming her quest to hike the PCT, Tarr says she found a new goal: to find these men and bring closure to their families. She joined the search in 2017.

Lankford, who was headed to the trail to look into Sylvia’s disappearance, heard about Tarr’s efforts and reached out, intrigued.

“She was like, ‘Who is this person who dropped everything to look for a stranger?,’ ” Tarr recalled during a phone call between still ongoing search expeditions for O’Sullivan. “She wanted to have dinner with me, and explained that she was an author, looking for inspiration. And she wanted to talk to me more.”

It took a while for Tarr to warm up to the idea of being the subject of what’s ostensibly a true crime book. But she eventually invited Lankford on a 16-mile “pre-search” hike and grilled the author on her intentions: “Do you think there’d be anything in the book that would pertain to hiker safety? Could it be a value in that way?”

“She said, ‘Yes, absolutely!’ And that’s when I changed my mind,” Tarr said.

Lankford was true to her word, crafting a book that satisfies and educates. It also paints a picture of the remarkable generosity of people along the trail, from Tarr to the so-called “trail angels” who take hikers in, to the volunteer scanners who pore over aerial photos of places where the lost hikers’ possessions or remains might be found.

The book is also a portrait of hope and resilience, especially when it comes to Langford, Tarr and the families of the missing.

Meanwhile, Tarr hasfounded a nonprofitto formalize her search for the PCT missing, and to provide support for other families of missing hikers; she’scurrently seeking donationsfor a search effort in August to look for O’Sullivan’s remains in a previously unexamined area.

“He is out there somewhere,” Tarr said of the lost hiker, with complete conviction in her voice. “He is in a place that not one other human being has been since April 2017. And that in itself is definitely a clue, isn’t it?”

Eve Batey is a freelance writer.