The most influential book by the patron saint of the wilderness movement, Muir’s lyrical book about exploring the Sierra Nevada radiates the joy of exploring the Sierra’s high country. The Mountains of California was written when the Sierra was still largely unheard of other than as an obstacle to gold rush settlers heading west. Muir combines both his journeys to the high peaks with an understanding of ecology—a groundbreaking concept at the time. Thousands flocked to Yosemite in the years that followed.