While it tells the story of Christopher McCandless's journey into the Alaskan wilderness, it's not a biography in the traditional sense. Krakauer uses McCandless's story as a springboard to explore broader themes like the nature of wilderness, the allure of self-reliance, and the complexities of human nature. He also investigates the historical context of McCandless's journey and analyzes his motivations.
While the book is grounded in factual events, Krakauer employs a combination of reporting, personal reflection, and narrative storytelling, making it more than just a straightforward account of McCandless's life.