Every important movement has a guiding force as a catalyst and John Muir was that catalyst for the environmental movement in the United States. John Muir (1838 - 1914) was a preservationist and environmentalist. He was the founder of the Sierra Club, which is one of the most influential organizations in the U S. His letters, essays and books were often written about nature and wildlife in the Sierra Mountains. His activism helped to save the Yosemite Valley and other wilderness areas. The work of John Muir was the foundation for the environmentalist movement. The letters and articles in this collection cover a 29 year period and areas in California-Utah-Nevada-Washington-Oregon-The Grand Canyon.