With the publication of David Thompson's Columbia Journals, Barbara Belyea gives wider recognition to the fur trader, primary explorer, and cartographer who lived from 1770 to 1857. His Columbia Journals not only documents the North West Company's efforts to find good trade routes across the Canadian Rocky Mountains but reveals Thompson's personal interest in mapping the Pacific watershed north of California. His accounts give a detailed picture of the fur business during its greatest expansion and remind us of the extent to which the territory he explored has been transformed by settlement, roads, and hydroelectric dams. Thompson's journals trace the fur trade's westernmost expansion while his hand-drawn maps preserve a contemporary image of the country he explored.