Fifteen years ago, Jon Krakauer captivated readers with the true story of Christopher McCandless, a young American whose wanderlust led him to Alaska and a mysterious, tragic end. Part of the book relates McCandless to another young man, Everett Ruess, an explorer, artist, and writer in the early part of the 20th century. Ruess disappeared in Utah under even more puzzling circumstances than McCandless, and to this day, his fate has never been definitely established. Now, author David Roberts tackles the 80-year-old mystery in a brand-new book (out July 19), Finding Everett Ruess.

At 20, Ruess and his two burros were exploring a Utah desert, far from civilization, when his family lost track of him. The burros were found, but to this day no trace of Ruess has ever been verified. Did he plan his own disappearence? Was he murdered? Did he fall and die in the wilderness? Lost diaries, weird "sightings," bone fragments, and DNA tests keep the tale unraveling, but Ruess remains forever 20 years old, an unsolved mystery and symbol of youthful longing and freedom.

For all who found the book and movie Into the Wild compelling, Jon Krakauer wrote the introduction to this book, so closely does he see the connection between McCandless and Ruess. Finding Everett Ruess may be the closest we ever come to really knowing what happened to a young man who once wrote, "I have not tired of the wilderness...it is enough that I am surrounded by beauty." The mystery of his fate still echoes today.