, the first full-length biography of mapmaker David Thompson (17701857), 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 Hudsons 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.Drawing extensively on Thompsons personal journals and illustrated with his detailed sketches, intricate notebook pages, and the map itself, charts the life of a man who risked everything in the name of scientific advancement and exploration.