In 1996, Outside Magazine writer Jon Krakauer released his first book titled Into the Wild. Built up from a piece he did for Outside, Krakauer’s nonfiction work detailed the life of Christopher McCandless, an idealistic college graduate who donated all of his savings to charity, dubbed himself “Alexander Supertramp” and embarked on an odyssey to experience the visceral interactions with the natural world that he thought were missing from most contemporary individuals’ existences. Two years later, McCandless was found dead of starvation in a bus landlocked in the Alaskan wilderness.

Krakauer’s national bestseller resonated with a number of individuals who were disenchanted with the readymade feeling of modern life. One of many uniquely affected by the work was actor and director Sean Penn, who saw McCandless’ life not as a flight but as a “pursuit of relentless authenticity.”

After reading Into the Wild, Penn immediately set about trying to obtain the rights to create a movie based on the book. At the time, the McCandless family was still raw from the loss of Christopher, and it took almost a decade before the young man’s relatives gave Penn the nod to make a film version of Christopher’s life.

Penn’s adaptation of Into the Wild takes different paths than Krakauer’s book. In the book version, Krakauer undertook Christopher’s journey himself but interspersed the details uncovered by his investigation with his own experiences in the wild and the true stories of little known individuals like Everett Ruess, a man who wrote that he preferred the “star-sprinkled sky to a roof” before disappearing into the Utah canyon lands in the 1930s.

Meanwhile, Penn’s film version of the story is told in a different manner. The movie is narrated with Christopher’s letters, whose words scroll across the screen like the puffy script of a skywriting airplane above the natural landscapes in the background, and the reminisces of the young wanderer’s sister Corine, played by Jena Malone.

One strength of Penn’s retelling is that with Corine’s narration the filmmaker effectively establishes a stronger motive for Christopher’s wanderings than Krakauer’s book established. At various times, Malone describes how Christopher was hit hard by discovering buried secrets about his parent’s relationship.

In the film, Christopher, who is portrayed by Emile Hirsch of Alpha Dog and Lords of Dogtown, travels through the melted chocolate plateaus of the American Southwest to his eventual demise under a tiara of snow-covered peaks in the Alaskan wilderness. Filmed on location throughout the Western United States, cinematographer Eric Gautier (The Motorcycle Diaries) fills the screen with enough postcard perfect natural vistas and shots of wildlife to make a National Geographic photographer envious.

Along the way, the young man meets a series of fellow dropouts who become a surrogate family. Among the most notable are Vince Vaughan as a charismatic South Dakota farmer and Catherine Keener, who portrays an aging hippie scarred by the disappearance of her own son.

Penn also comes up with a few painfully evocative moments in the film. One finds Christopher wandering around amongst the homeless of Los Angeles and wistfully staring into a bar, where he can easily see himself among the successful young business types. In another scene that illustrates the indifference of the natural world, Christopher, who is starving in the Alaskan outback, kills a moose that quickly becomes inedible due to an infestation of flies and maggots.

But the problem with the way that Penn tells Christopher’s story is the way it moves jarringly backward and forward in a nonchronological manner. The scenes are seemingly arbitrarily lumped together in chapters, and in too many latter scenes, Christopher’s fellow dropouts seem to be there just to hammer home a theme about the importance of family. Also, clocking in at 140 minutes long, Penn’s journey – like Christopher’s foray into the natural world – lasts a bit too long.

Still, Penn’s film, which features real life appearances by American outsiders including the man who built the quirky “Salvation Mountain” in the California desert, is a moving – and fittingly idiosyncratic – tribute to America’s remaining wild places and the individuals who reside there.

INTO THE WILD ( * * 1/2)

Directed by Sean Penn • Starring Emile Hirsch, Marcia Gay Harden, William Hurt and Jena Malone • R, 140 min • At the Osio Cinemas.