Peter Matthiessen (May 22, 1927 - April 5, 2014) 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.

In 2008, at age 81, Matthiessen received the National Book Award for Fiction for Shadow Country, a one-volume, 890-page revision of his three novels set in frontier Florida that had been published in the 1990s. According to critic Michael Dirda, "No one writes more lyrically [than Matthiessen] about animals or describes more movingly the spiritual experience of mountaintops, savannas, and the sea."

Matthiessen was treated for acute leukemia for more than a year. His death came as he awaited publication of his final novel, In Paradise on April 8.

A classic work of nature and humanity, by renowned writer Peter Matthiessen (1927-2014), author of the National Book Award-winning The Snow Leopard and the new novel In Paradise

Peter Matthiessen crisscrossed 20,000 miles of the South American wilderness, from the Amazon rain forests to Machu Picchu, high in the Andes, down to Tierra del Fuego and back. He followed the trails of old explorers, encountered river bandits, wild tribesmen, and the evidence of ancient ruins, and discovered fossils in the depths of the Peruvian jungle. Filled with observations and descriptions of the people and the fading wildlife of this vast world to the south, The Cloud Forest is his incisive, wry report of his expedition into some of the last and most exotic wild terrains in the world.

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