John Muir (21 April 1838 – 24 December 1914) was a Scottish-American naturalist, author, environmental philosopher 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 of California, have been read by millions. His activism helped to preserve the Yosemite Valley, Sequoia National Park and other wilderness areas. The Sierra Club, which he founded, is a prominent American conservat