Enos Mills (1870-1922) was the quintessential voice of the Rocky Mountains in the early decades of the twentieth century, and he achieved fame as a naturalist and nature writer, conservation pioneer, lecturer, and mountain adventurer. Enos Mills: Citizen of Nature is the first full-length examination of Mills and his work, an incisive account of a complex, controversial, and often difficult man who touched millions of lives in his time and whose legacy has great relevance today.