In his book about the life and death of Chris McCandless, Into the Wild, Jon Krakauer quotes the words "Jack London is King," which McCandless carved into a piece of wood and signed with his nickname, Alexander Supertramp, in 1992, the last year of his life.
This shows McCandless's appreciation of at least some of the works of Jack London. London wrote a great deal during his short career, but his most famous books and stories, such as The Call of the Wild and "To Build a Fire," are set in harsh, unforgiving outdoor environments in North America. These were precisely the type of lonely places McCandless liked to explore, and it is not surprising that he found inspiration in London's descriptions of the hostile and majestic landscape.
There is an irony, however, in the fact that one of London's major themes is the folly and arrogance of those who underestimate the challenges of these lonely places. His best-known short story, "To Build a Fire," tells a story of death* in the wilderness that is eerily close to McCandless's own. This suggests that McCandless was not a particularly subtle reader, enjoying the spectacular setting of London's works but failing to heed their message.
*This refers to the most famous version of the story, published in 1908. There is an earlier version, in which the protagonist survives.