Submitted by EBriggs on Thu, 2013-02-14 22:57
David Thompson (1770–1857), a British-Canadian furtrader and surveyor, mapped 3.9 million square kilometers of North America. Navigating the full length of the Columbia River in 1811, he produced a high-quality map of the river basin. He has been called the greatest land geographer who ever lived.
Reference: MPC 71349