Ryan Cook has come a long way from making movies as a 6-year-old in his native Waterville to soon launching the world premiere of his film, “Lost on a Mountain in Maine,” July 13 at the Waterville Opera House.

Cook is one of the producers of the feature film, being screened as part of the upcoming Maine International Film Festival. It is the story of Donn Fendler, who in 1939 at age 12, got lost on Mount Katahdin while hiking with his family. He endured nine days in the wilderness while search parties scoured the terrain, lost 20 pounds and eventually made his way out of the woods to safety.

Based on the book, “Donn Fendler: Lost on a Mountain in Maine,” by Fendler, as told to Joseph B. Egan, the film was a yearslong labor of love for Cook, who aspired to be a filmmaker as a young child and now is location manager for films being shot in Boston. His has been a long and fruitful career, starting when he was a junior at Waterville High School in 2003 and taking a film course.

He landed a non-paid position as a production assistant for the HBO movie “Empire Falls,” which was filmed mostly in Waterville and Skowhegan and starred Paul Newman, Joanne Woodward, Ed Harris and Aidan Quinn. Cook, then 17, would arrive on set at 4 a.m., work until 7:30 a.m., go to school until 2 p.m. and then return to the movie set to work until 11 p.m. This went on for three months.

A news clipping from the Morning Sentinel published Oct. 3, 2003. Newspapers.com clipping

A news clipping from the Morning Sentinel published Oct. 3, 2003. Newspapers.com clipping

Cook was a go-getter, and an enthusiastic one. I interviewed him for a story in 2003 about the filming of “Empire Falls,” based on the Pulitzer Prize-winning book of the same name by Richard Russo, who wrote the book while he taught at Colby College.

Cook did every chore imaginable as part of the movie crew, from keeping crowds back as stars appeared on city streets to be filmed, to taking out the trash. He performed every task asked of him and more, all the while peppering crew members with questions about their work. He wanted to learn the film industry, inside and out.

The next year, in 2004, Cook made a film that was shown at the Maine International Film Festival and won the grand prize for the student film section of the festival. His prize was being able to attend a weeklong seminar at Maine Media Workshops in Rockport, where he had the opportunity to learn more about filmmaking from experts.

He was hooked. After graduating from Waterville High, he enrolled in Emerson College in Boston, where he earned a bachelor’s degree in film production and film management in 2009.

While in college, he started working on movies in Boston. He became a film location manager and has worked on many films over the last 15 years, including the 2010 movie “Knight and Day,” with Cameron Diaz and Tom Cruise; the 2012 film “Ted,” starring Mark Wahlberg; and the 2023 movie “Boston Strangler,” with Keira Knightley. He also worked on the television miniseries “Dexter.”

As a fourth-grader in Waterville many years prior, Cook had read Fendler’s book and Fendler himself came to Cook’s classroom to talk about his Katahdin experience. Cook, who had made 75 little films as a child with his father’s guidance, was mesmerized and became obsessed with the idea of making a film about Fendler.

Donn Fendler is shown at his Newport home in 2014. File photo by Ryan Cook

While at Emerson, Cook became friends with Derek Desmond of Shelburne, New Hampshire, and in 2010, they drove up to Newport, Maine, to meet Fendler, a fortuitous joining of the minds that would lead to a longtime friendship. Fendler trusted the pair, who recorded many meetings with him, traveled to schools and other events around Maine for Fendler’s speaking engagements, and recorded those also in their quest to make a documentary film.

Cook and Desmond became so close to Fendler that eventually when they met, they would talk about things other than the documentary.

“He really became like family to us,” Cook said in an interview Tuesday.

In 2011, Cook and Desmond’s hourlong documentary about Fendler was shown at the Maine International Film Festival, netting the audience award. They continued to work on a feature film about Fendler, who was on board but died in 2016 at age 90 and did not see the 16-year effort come to fruition.

But, according to Cook, Fendler was confident it would happen.

“I said, ‘Donn, we’re not the people to go away,’ ” Cook recalled. “I promise you that we’re going to stick this thing through.”

A movie still from the upcoming film “Lost on a Mountain in Maine,” about Donn Fendler. Photo courtesy of Ryan Cook

The film, he said, is an adventure film and a family movie that incorporates the book’s story as well as interviews and recordings with Fendler.

“This is not based on a true story — this is a true story,” he said.

Cook, Desmond and director Andrew Boodhoo Kightlinger, will be at the premiere to answer questions after the showing. Actors Caitlin Fitzgerald, Luke David Blumm and Paul Sparks also will be there. Fendler family members are scheduled to come from all over the U.S. to see the film, which will come out in movie theaters Nov. 1, a date Cook said he was announcing for the first time. The film is being produced by Sylvester Stallone and his company, Balboa Productions. The main producer is Dick Boyce and additional producers are Braden Aftergood and Heather Grehan. Blue Fox is the distributor.

Producer Ryan Cook, left, and Maine Film Center Executive Director Michael Perreault confer about the upcoming showing of Cook’s 98-minute feature film “Lost on a Mountain in Maine.” The film is being shown at the Waterville Opera House during the upcoming Maine International Film Festival in Waterville. Rich Abrahamson/Morning Sentinel

Cook, now 37, was heading to Katahdin on Thursday from Waterville to hike the mountain, which he said he has climbed about every year since he was 10. He feels he has come full circle, returning to Waterville to present the film, he said.

“It was important for us to really showcase it in front of a Maine audience because I know how much it means to Maine,” he said. “Being able to do it in my hometown is the cherry on top of it all.”

Amy Calder has been a Morning Sentinel reporter 35 years. Her columns appear here Saturdays. She is the author of the book, “Comfort is an Old Barn,” a collection of her curated columns, published in 2023 by Islandport Press. She may be reached at acalder@centralmaine.com. For previous Reporting Aside columns, go to centralmaine.com.