By DAVID SHARP

PORTLAND, Maine (AP) — Most Maine schoolchildren know the boy who got lost for more than a week in 1939 after climbing the state’s tallest mountain. Now the rest of the United States is joining the story.

Opening at 650 movie In theaters Friday, “Lost on a Maine Mountain” tells the heartbreaking story of a 12-year-old boy Don Fendlerwho spent nine days on Mount Katahdin and the surrounding desert before being rescued. The gripping story of survival captured the nation’s attention in the days before World War II, and the boy’s bravery earned him a president’s award.

For decades, Fendler and Joseph B. Egan’s book, published the same year as the rescue, has been required reading in many Maine classrooms, like that of third-grade teacher Kimberly Nielsen.

“I love that the overall theme is that Donn never gave up. He just never gives up. He comes and goes,” said Nielsen, a teacher at Crooked River Elementary School in Casco, who also read the book several times with her own children.

Separated from his hiking group due to bad weather atop Mount Katahdin, Fendler used techniques learned as a Boy Scout to survive. He made his way through the woods to the east branch of the Penobscot River, where he was found more than 30 miles (48 kilometers) from where he started. Bruised and cut, starved and without pants or shoes, he survived nine days eating berries and lost 7 kilograms (15 pounds).

The boy’s danger sparked a massive search and he was the focus of newspaper headlines and late-night radio broadcasts. Hundreds of volunteers flocked to the region to help.

The film is based on the children’s book, as told to Egan by Fendler, drawing on additional interviews and archival footage to reinforce the importance of family, faith and community during difficult times, director Andrew Boodhoo Kightlinger said.

“Times are dark in the country in a strange way. You know, there are political divisions, society is a little nervous and everything. And I thought, here’s a movie that reminds people of the power of community, the power of caring about your neighbors. And the topics were very basic and simple. And for some reason, sometimes we seem to remember those things,” he said.

The film brings a vintage vibe to the big screen.

Filming took place in the woods of upstate New York, with the crew battling bugs and wading through shoulder-deep water for scenes in a canoe. Other scenes were filmed on Mount Katahdin and on a replica mountaintop built on a soundstage, with lichen-covered granite stones, wind, rain and lightning.

The film offers the perspective of the distraught family and the terrified child, played by Luke David Blumm. His father is played by Paul Sparks (“House of Cards,” “Boardwalk Empire”). Maine native Caitlin FitzGerald (“Masters of Sex,” “Succession”), who read the book and knew Fendler as a child, takes on the role of Donn’s mother.

FitzGerald isn’t the only Mainer involved in the film. Producer Ryan Cook, who also grew up in Maine, teamed up with another Mainer, Dick Boyce. Both were familiar with the book and Cook became close to Fendler and previously produced a documentary about him.

Fendler was generous with his time and often told his story at school assemblies. “I tell each of them that they have something inside that they don’t know they have,” he told The Associated Press in 2011, five years before his death at age 90. “When it comes to a bad situation, Let’s find out how strong people are in heart and mind; That is called the will to live.”

Sylvester Stallone Balboa Productions accepted the project because they liked the story of the brave underdog.

Kightlinger, who accompanied Katahdin to audition for the film’s directing position, said adventure stories abound. This one, he believes, was strengthened by the backstory of the difficulties Donn and his father had connecting.

“Ultimately, this is a kid who just wants a hug from his dad,” Kightlinger said. “That’s such a pure and simple message, and I think more films should aspire to do that and remind people of the simple things, because there’s so much noise in our world right now and the simple things sometimes get lost.”

Nielsen said the story is fascinating and practical. In her classroom, the book inspires discussions about geography, plants, and wildlife; preparedness and survival skills; and resilience in the face of adversity.

Your teen learned a valuable lesson from the book: staying together in nature.

The 16-year-old was climbing Mount Katahdin with friends a few weeks ago. After walking over the trees, they were crossing rocks when a storm blew up. The three made the difficult decision as a group to return.

“My son wanted to move on, but he knew they had to stay together. He learned that lesson from the book. “I am 100% sure,” she said.