John Muir (1838-1914), US naturalist, traveller, writer and geologist. Muir was born in Scotland and emigrated to the USA with his family in 1849. After travelling the country, he arrived in 1868 in Yosemite Valley, California, and was instantly captivated by the beauty of the area. He spent years working in the area and studying its geology and natural history. He proposed a theory that glaciers had sculpted the valley, and was eventually proved right. Muir also worked to protect Yosemite, persuading President Roosevelt to support the protection of Yosemite in a National Park. Painting made c. 1917 from a 1909 photograph by Orlando Rouland (1871-1945).