In April 1992, Chris McCandless arrives in a remote area called Healy, just north of Denali National Park and Preserve in Alaska. Noting McCandless' unpreparedness, the man who drops him off gives him gumboots.
McCandless sets up camp in an abandoned city bus that he calls "The Magic Bus". He is content with the isolation, the beauty of nature, and the thrill of living off the land. He hunts with a .22, reads books, and keeps a journal as he prepares his new life in the wild.
Flashback
In May 1990, McCandless graduates with high honors from Emory University. He is disenchanted with modern society after discovering he and his sister Carine were born out of wedlock.
McCandless destroys his credit cards and identification, donates his savings to Oxfam and sets out on a cross-country drive in his Datsun 210 to experience life in the wilderness. He does not tell his parents or Carine what he is doing or where he is going and does not contact them after his departure. This causes his parents to become increasingly anxious.
At Lake Mead, McCandless' car is caught in a flash flood; he abandons it and begins hitchhiking. Burning what remains of his cash, he assumes the name "Alexander Supertramp". In Northern California, McCandless encounters hippie couple Jan and Rainey. Rainey tells him his relationship with Jan is failing, which McCandless helps rekindle.
In September, McCandless arrives in Carthage, South Dakota, and works for a contract harvesting company owned by Wayne Westerberg. He leaves after Westerberg is arrested for satellite piracy.
McCandless kayaks down the Colorado River and, though told by park rangers he may not do so without a license, ignores their warnings and goes downriver to Mexico. His kayak is lost in a dust storm, and he crosses back into the United States on foot. Unable to hitch a ride, he jumps on freight trains to Los Angeles. Not long after arriving, however, he starts feeling "corrupted" by modern civilization and leaves. He is forced to resume hitchhiking when railroad police catch and beat him.
In December 1991, McCandless arrives at Slab City, in the Imperial Valley, and encounters Jan and Rainey again. He also meets Tracy Tatro, a teenage girl who shows interest in him, but he turns her down because she is a minor. After the holidays, McCandless continues heading for Alaska.
One month later, camping near Salton City, McCandless meets Ron Franz, a retired widower who lost his family in a car accident while he was serving in the United States Army. He leads a lonely life in a workshop as a leather worker. Franz teaches McCandless leatherwork, resulting in the making of a belt detailing his travels.
After two months with Franz, McCandless decides to leave for Alaska. Franz gives McCandless his old camping and travel gear, along with an offer to adopt him as his grandchild. McCandless tells him they should discuss it after he returns from Alaska.
Flashforward
Four months later, at the abandoned bus, life for McCandless becomes harder, and he makes several poor decisions. Trying to live off the land, he hunts down a large moose with his rifle, but cannot preserve the meat and it spoils within days. As his supplies dwindle, he realizes that nature can be harsh.
McCandless concludes that true happiness can be found only when shared with others, and he seeks to return from the wild to his friends and family. However, he finds that the stream he crossed during the winter has become wide, deep, and violent due to the thaw, and he is unable to cross. Defeated, he returns to the bus.
In a desperate act, McCandless gathers and eats roots and plants. He confuses similar plants and eats a poisonous one, falling sick as a result. Slowly dying, he continues to document his process of self-realization, and imagines what it might have been like if he had managed to return to his family. He writes a farewell note to the world and crawls into his sleeping bag to die.
Two weeks later, moose hunters find his body. Shortly afterwards, Carine returns to Virginia with her brother's ashes in her backpack.
