In 1849, 11-year-old John Muir immigrated from Scotland to America. Here, he rose from farmer and sawmill worker to become a noted authority on the botany, glaciers, and forestry of the nation's wilderness. Best known for his long association with the Yosemite Valley and Sierra Nevada Mountains of California, Muir also explored, mostly afoot, the southern States, Alaska, the Great Basin, and the Mojave Desert. His studies of nature took him around...