John Muir was born in Dunbar, Scotland, to Daniel Muir and Ann Gilrye. His early life was steeped in strict religious upbringing and rigorous outdoor work on his family's farm. This early exposure to nature, even under demanding circumstances, fostered a deep appreciation for the natural world that would later define his life's work.

The Muir family emigrated to the United States, settling on a farm near Portage, Wisconsin. This move exposed the young Muir to the vast, untouched landscapes of the American frontier, further igniting his love for the wilderness. He quickly adapted to farm life and invented numerous labor-saving devices, showcasing his ingenuity and resourcefulness.

Muir attended the University of Wisconsin, where he studied botany, geology, and chemistry. Although he never officially graduated, his time at the university exposed him to scientific thinking and deepened his understanding of the natural world. He considered his true education to come from his explorations of the surrounding natural areas.

Following an industrial accident that temporarily blinded him, Muir embarked on a transformative journey: a thousand-mile walk from Indiana to the Gulf of Mexico. This solo trek solidified his commitment to living in and studying nature. His journal entries from this journey later became a published book, introducing his captivating writing style and observations to a wider audience.

Muir arrived in Yosemite Valley, California, and immediately fell in love with its stunning beauty. He spent years exploring the valley, studying its geology, flora, and fauna. His intimate knowledge of Yosemite allowed him to develop theories about its glacial formation, challenging prevailing scientific views and establishing him as a respected geologist and naturalist.

Recognizing the increasing threats to wilderness areas, particularly Yosemite, Muir founded the Sierra Club. This organization became a powerful force in the conservation movement, advocating for the protection of wildlands and promoting responsible outdoor recreation. Muir served as its first president, guiding its early efforts to preserve natural areas.

Muir camped with President Theodore Roosevelt in Yosemite, personally guiding him through the park's wonders and emphasizing the urgent need for its protection. This influential trip played a significant role in Roosevelt's decision to expand the national park system and establish further conservation measures. It remains a symbol of the power of direct experience in shaping policy.

John Muir died in Los Angeles, California, at the age of 76. He died of pneumonia, after a trip to visit his daughter in December. He left behind a legacy of conservation and environmental stewardship that continues to inspire generations. His writings, advocacy, and tireless dedication to preserving wilderness have had a profound impact on the American landscape and the global environmental movement.