John Muir (1838-1914), also known as 'John of the Mountains' and 'Father of the National Parks', was an influential Scottish-American naturalist, author, environmental philosopher, glaciologist, and early advocate for the preservation of wilderness in the US. His activism helped preserve the Yosemite Valley, Sequoia National Park and many other wilderness areas, and the Sierra Club, which he co-founded in 1892, remains a prominent conservation organization. The spiritual quality and enthusiasm for nature expressed in his writings has inspired readers, including presidents and congressmen, to take action to preserve large nature areas. Muir's family emigrated from Scotland to the US in 1849, starting a farm in Portage, Wisconsin, and aged 22 Muir enrolled at the University of Wisconsin-Madison. Although he never graduated he learned enough geology and botany to inform his later wanderings. Muir first came to California in 1868 and devoted six years to the study of the Yosemite Valley. After working in Nevada, Utah, and Colorado, he returned to California in 1880 and made his home there. In The Mountains of California (1894) he pays tribute to the beauties of the Sierra, recounting not only his own journies by foot through the mountains, glaciers, forests, and valleys, but also the geological and natural history of the region, ranging from the history of the glaciers, the patterns of tree growth, and the daily life of the animals and insects. With 66 black and white illustrations from engravings and photographs.