Drawing on a vast array of correspondence, interviews, and published and unpublished works, Spaulding illuminates Adams's place in modern art and the environmental movement. He explores the photographer's early influences - the tensions in Adams's once-wealthy family, his adventures in the Sierra Nevada, and his participation in the art colonies of California and New Mexico.

His friendships with leading artists, including Dorothea Lange, Georgia O'Keefe, Alfred Stieglitz, Paul Strand, and Edward Weston, fostered an exploration of issues such as modernism, photography as art, and the social responsibility of artists and individuals. In his thirty-seven years as a director of the Sierra Club, he helped the environmental movement grow from a small band of activists to a force of international prominence.