Epic Wanderer, the first full-length biography of mapmaker David Thompson (1770-1857), is set in the late eighteenth and early nineteenth centuries against the broad canvas of dramatic rivalries between the United States and British North America, between the Hudson's Bay Company and its Montreal-based rival, the North West Company, and among the various First Nations thrown into disarray by the advent of guns, horses, and alcohol. Less celebrated than his contemporaries Meriwether Lewis and William Clark, Thompson spent nearly three decades, beginning in 1784, surveying and mapping more than 1.2 million square miles of largely uncharted Indian territory. Traveling across the prairies, over the Rockies, and on to the Pacific, Thompson transformed the raw data of his explorations into a map of the Canadian West. Measuring ten feet by seven feet and exhibiting astonishing accuracy, the map became essential to the politicians and diplomats who would decide the future of the rich and promising lands of the West. Yet its creator worked without personal glory and died in penniless obscurity. Drawing extensively on Thompson's personal journals and illustrated with his detailed sketches, intricate notebook pages, and the map itself, Epic Wanderer charts the life of a man who risked everything in the name of scientific advancement and exploration.