John Muir (April 21, 1838 – December 24, 1914) was one of the first modern preservationists. His letters, essays, and books telling of his adventures in nature, and wildlife, especially in the Sierra Nevada Mountains of California, were read by millions and are still popular today. His direct activism helped to save the Yosemite Valley and other wilderness areas. The Sierra Club, which he founded, is now one of the most important conservation organizations in the United States. His writings and philosophy strongly influenced the formation of the modern environmental movement.

Biography
In 1888 after seven years of managing the ranch his health began to suffer. With his wife's prompting he returned to the hills to recover his old self, climbing Mt Rainier and writing "Ascent of Mount Rainier".
Muir travelled with the party that landed on Wrangell Island on the USS Corwin and claimed that island for the United States in 1881. He documented this experience in his book The Cruise of the Corwin.

Muir's travels in the Northwest

From studying to protecting
Muir threw himself into his new role with great vigor. He envisioned the Yosemite area and the Sierras as pristine lands. He saw the greatest threat to the Yosemite area and the Sierras to be livestock, especially domestic sheep (calling them "hoofed locusts"). In June 1889, the influential associate editor of Century magazine, Robert Underwood Johnson, camped with Muir in Tuolumne Meadows and saw firsthand the damage a large flock of sheep had done to the grassland. Johnson agreed to publish any article Muir wrote on the subject of excluding livestock from the Sierra high country. He also agreed to use his influence to introduce a bill to Congress that would make the Yosemite area into a national park, modeled after Yellowstone National Park.
A bill essentially following recommendations that Muir put forward in two Century articles ("The Treasure of the Yosemite" and "Features of the Proposed National Park", both published in 1890), was passed by Congress on September 30, 1890. To the dismay of Muir, however, the bill left Yosemite Valley in state control. With this partial victory under his belt, Muir helped form an environmental organization called the Sierra Club on May 28, 1892 and was elected as its first president (a position he held until his death 22 years later). In 1894 his first book, The Mountains of California, was published.

Preservation Efforts
In July of 1896 Muir became good friends with another leader in the conservation movement, Gifford Pinchot. That friendship was ended late in the summer of 1897 when Pinchot released a statement to a Seattle newspaper supporting sheep grazing in forest reserves. Muir confronted Pinchot and demanded an explanation. When Pinchot reiterated his position Muir told him "I don't want any thing more to do with you." This philosophical divide soon expanded and split the conservationist movement into two camps: the preservationists, led by Muir, and Pinchot's camp, who co-opted the term "conservationist." Muir was deeply opposed to commercializing nature. The two men debated their positions in popular magazines as Outlook, Harper's Weekly, Atlantic Monthly, World's Work, and Century. Muir argued for the preservation of resources for their spiritual and uplifting values; Pinchot saw conservation as a means of intelligently managing the nation's resources. Both men opposed reckless exploitation of natural resources, including clear-cutting of forests.
In 1899, Muir accompanied railroad executive E. H. Harriman and other esteemed scientists on Harriman's famous exploratory voyage along the Alaska coast aboard the luxuriously refitted 250-foot steamer called the George W. Elder. He would later rely on his friendship with Harriman to apply political pressure on Congress to pass conservation legislation.
In 1903 President Theodore Roosevelt accompanied Muir on a visit to the park. Muir joined Roosevelt in Oakland, California for the train trip to Raymond. The presidential entourage then traveled by stagecoach into the park. While traveling to the park, Muir told the president about state mismanagement of the valley and rampant exploitation of the valley's resources. Even before they entered the park, he was able to convince Roosevelt that the best way to protect the valley was through federal control and management.
After entering the park and seeing the magnificent splendor of the valley, the president asked Muir to show him the real Yosemite. Muir and Roosevelt set off largely by themselves and camped in the backcountry. While circling around a fire, the duo talked late into the night, slept in the brisk open air and were dusted by a fresh snowfall in the morning - a night Roosevelt never would forget.
Muir then increased efforts by the Sierra Club to consolidate park management and was rewarded in 1905 when Congress transferred the Mariposa Grove and Yosemite Valley into the park. His wife Louisa died on 6 August 1905.

Preservation vs Conservation
Pressure started to mount to dam the Tuolumne River for use as a water reservoir for San Francisco. The damming of Hetch Hetchy Valley was passionately opposed by Muir who called Hetch Hetchy a "second Yosemite." Muir, the Sierra Club and Robert Underwood Johnson fought against inundating the valley and Muir even wrote Roosevelt pleading for him to scuttle the project. After years of national debate that polarized the nation, Roosevelt's successor, Woodrow Wilson signed the dam bill into law on December 19, 1913. Muir felt a great loss from the destruction of the valley, his last major battle.
John Muir died in Los Angeles on December 24, 1914 of pneumonia

Hetch Hetchy and the Legacy of John Muir
Two John Muir Trails (in California and Tennessee), the John Muir Wilderness, the Muir Woods National Monument, John Muir High School, John Muir College (a residential college of the University of California, San Diego), and John Muir Country Park in Dunbar are named in his honor, as is the asteroid 128523 Johnmuir. An image of John Muir, with the California Condor and Half Dome, appears on the California state quarter which was released in 2005. A quote of his appears on the reverse side of the Indianapolis Prize Lilly Medal for conservation.
On December 6, 2006, California Governor Arnold Schwarzenegger and First Lady Maria Shriver inducted John Muir into the California Hall of Fame located at The California Museum for History, Women, and the Arts.

Criticism
"Most people are on the world, not in it; have no conscious sympathy or relationship to anything about them, undiffused, separate, and rigidly alone like marbles of polished stone, touching but separate."

Quotes

Primary sources

Ehrlich, Gretel (2000). John Muir: Nature's Visionary. National Geographic. ISBN 0-7922-7954-9. 
Fox, Stephen (1981). John Muir and His Legacy: The American Conservation Movement. Little, Brown and Company. ISBN 0-316-29110-2. 
Meyer, John M. (1997). "Gifford Pinchot, John Muir, and the Boundaries of Politics in American Thought". Polity 30 (2): 267-284. ISSN 0032-3497. 
Miller, Char (2001). Gifford Pinchot and the Making of Modern Environmentalism. Island Press. ISBN 1-55963-822-2. 
Smith, Michael B. (June 1998). "The Value of a Tree: Public Debates of John Muir and Gifford Pinchot". The Historian 60 (4): 757-778. ISSN 0018-2370. 
Turner, Fredrick (1985). Rediscovering America, John Muir in His Time and Ours. Viking Press. ISBN 0-87156-704-0. 
Williams, Dennis (2002). God's Wilds: John Muir's Vision of Nature. Texas A&M University Press. ISBN 1-58544-143-0. 
Wolfe, Linnie Marsh (1945). Son of the Wilderness: The Life of John Muir. University of Wisconsin Press. ISBN 0-299-18634-2. 
Worster, Donald (January 2005). "John Muir and the Modern Passion for Nature". Environmental History 10(1): 8-19. 
Wuerthner, George (1994). Yosemite: A Visitor's Companion. Stackpole Books, 25-37. ISBN 0-8117-2598-7.  See also

Sachs, Aaron (2006). The Humboldt Current: Nineteenth-Century Exploration and the Roots of American Envionmentalism. Viking Press. ISBN 0-670-03775-3.  Muir is one of four people the author focuses on who were influenced by Alexander von Humboldt.