John Muir was a Scottish-born American naturalist, author, and early advocate of preservation of wilderness in the United States. His letters, essays, and books telling of his adventures in nature, especially in the Sierra Nevada mountains of California, have been read by millions. His activism helped to save the Yosemite Valley, Sequoia National Park and other wilderness areas. The Sierra Club, which he founded, is now one of the most important conservation organizations in the United States. One of the most well-known hiking trails in the U.S., the 211-mile John Muir Trail, was named in his honor. Other places named in his honor are Muir Woods National Monument, Muir Beach, John Muir College, Camp Muir and Muir Glacier.

In his later life, Muir devoted most of his time to the preservation of the Western forests. He petitioned the U.S. Congress for the National Park Bill that was passed in 1899, establishing both Yosemite and Sequoia National Parks. Because of the spiritual quality and enthusiasm toward nature expressed in his writings, he was able to inspire readers, including presidents and congressmen, to take action to help preserve large nature areas. He is today referred to as the "Father of the National Parks," and the National Parks Service produced a short documentary on his life.

Muir's biographer, Steven Holmes, states that Muir has become "one of the patron saints of twentieth-century American environmental activity," both political and recreational. As a result, his writings are commonly discussed in books and journals, and he is often quoted in books by nature photographers such as Ansel Adams. Muir was noted for being an ecological thinker, political spokesman, and religious prophet, whose writings became a personal guide into nature for countless individuals, making his name "almost ubiquitous" in the modern environmental consciousness. According to author William Anderson, Muir exemplified "the archetype of our oneness with the earth."

(from Wikipedia)