Peter Matthiessen was an American novelist, naturalist, wilderness writer and CIA agent. A co-founder of the literary magazine The Paris Review, he was a 2008 National Book Award winner. He was also a prominent environmental activist. His nonfiction featured nature and travel, notably The Snow Leopard (1978) and American Indian issues and history, such as a detailed and controversial study of the Leonard Peltier case, In the Spirit of Crazy Horse (1983). His fiction was adapted for film: the early story "Travelin' Man" was made into The Young One (1960) by Luis Buñuel and the novel At Play in the Fields of the Lord (1965) into the 1991 film of the same name.