John Muir (1838-1914) was a Scottish-American naturalist, author, environmental philosopher, and early advocate for the preservation of wilderness in the United States. His letters, essays, and books describing his adventures in nature, especially the Sierra Nevada mountains 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 leading American conservation organization. One of Muir's most notable works is 'My First Summer in the Sierra' (1911), which details his experiences during a season tending sheep and exploring the Sierra. Replete with original drawings and photographs, this book captures the essence of Muir's profound love for the outdoors and is a seminal text for wilderness conservation. Muir's literary style combines lyrical prose with keen observations and a deep spiritual reverence for nature. His works not only continue to inspire environmental movements but also serve as crucial historical documentation of the American wilderness at a time before industrialization altered the landscape. His dedication has earned him the moniker 'Father of the National Parks,' and his legacy endures through the ongoing work of the Sierra Club and the protection of natural spaces worldwide.