Thompson, David, fur trader (Apr. 30, 1770-Feb. 10, 1857). Born at Westminster, England, he became "one of the greatest practical land geographers the world has ever known," as much interested in mapping and exploration as he was in fur trading, his ostensible occupation. Much of his finest work was in Canada, but he also traveled and explored in the northwest of what is now the U.S., erecting establishments, tracing the course of the Columbia and other major bodies of water and rivers of the north and west; "he laid the foundation for much of the great fur trade" of the Northwest. At 14 he was bound to the Hudson's Bay Company and shipped to Fort Churchill on Hudson Bay. There and elsewhere he became a wilderness man, highly intelligent, curious, able and swiftly seasoned. He accompanied a party that opened traded with the Blackfeet in 1787-1788, learned surveying, explored and opened routes between Canadian posts, and in 1797 joined the North West Company, conducting a major mapping tour west of Lake Superior, and accurately charting the boundaries of the lake itself. He married a Scot-Cree woman in 1799, fathering five children and remaining loyal to her all his life. After repeated attempts, he managed to cross the Rockies in 1807 south of Alexander McKenzie's crossing, though he was not the first to accomplish this. He wintered at Windermere Lake, building a post, the first on the upper Columbia. In the spring he voyaged by canoe part way down the stream, and later that summer traced almost its entire route. He gave the name, via his French Canadians, to the Nez Perces, introduced firearms among the various tribes, and was very active for several seasons as trader as well as explorer. He reached the mouth of the Columbia July 15, 1811, after the Astorians had commenced construction of their post, although his arrival at that point was never his principal aim, for his business was trading and locating new fur country. He returned to Fort William on Lake Superior July 12, 1812, and never went back to the west. At Montreal he completed a great map of the western lands he had explored and surveyed. Thomson settled in Quebec, later in Ontario. From 1817 to 1827 he worked for the British Boundary Commission surveying the U.S. boundary as far west as Lake of the Woods; from 1834 to 1840 he surveyed lands in eastern Canada. He died, impoverished and in poor health, virtually blind, at Montreal, where he is buried. He was all but forgotten for many years, but his accurate maps and notes were widely used anonymously until Joseph B. Tyrell uncovered Thompson's notebooks, his huge manuscript map, and his narrative in the 1800s. In 1916 he published Thompson's narrative, and publication of his field journals was accomplished piecemeal later, so that Thompson gradually is coming into the widespread recognition he deserves.