After graduating from Emory University, top student and athlete Christopher McCandless abandons his possessions, donates his $24,000 college fund to charity, and hitchhikes to Alaska to live in the wilderness. Along the way, Christopher encounters a series of characters that shape his life. He works for a farmer in South Dakota, paddles a canoe down the Colorado River, and even spends time in a hippie community in Slab City, California. Each step of his journey is driven by his desire for freedom and adventure, but also reflects his disdain for the materialism and conventions that he perceives to be endemic in modern American life.

As Christopher travels across the country, he adopts the name Alexander Supertramp, embracing a nomadic lifestyle and the beauty of unspoiled nature. His odyssey takes him through a variety of American landscapes and climates, testing his ability to survive in the natural world, away from the comforts and safety of modern society. His interactions with the people he meets on the road profoundly affect both him and those whose lives he touches, each influencing his evolving philosophy and the decisions he makes about his life and journey to the Alaskan wilderness.