Nearly a century after John Muir’s death, his works remain in print, his name is familiar, and his thought is much with us. How Muir’s life made him a leader and brought him insights destined to resonate for decades is the central question underlying this biography by Thurman Wilkins. Profoundly attached to dramatic wild places and plants, and to the Sierra and the redwoods in particular, Muir spearheaded efforts to protect forest areas and have some designated as national parks. Muir’s wilderness ethic, as revealed in his books, letters, and journals, rests on his conception of the proper relationship between human culture and wild nature as one of humility and respect for all life.