David Thompson’s Surveying and Mapping of the Northwest of North America

The American Society of Civil Engineers and the Canadian Society for Civil Engineering have just jointly designated “David Thompson’s Surveying and Mapping of the Northwest of North America” as an International Historic Civil Engineering Landmark. David Thompson (1770–1857)—surveyor, map-maker, explorer, and fur trader for both the Hudson’s Bay and North West Companies—is considered “the greatest land geographer that the world has produced” (Tyrrell in David Thompson’s narrative of his explorations in Western America. The Champlain Society, Toronto, 1916, [13]), despite his serious visual impairment. Often accompanied by his Métis wife, Charlotte Small, he surveyed and mapped a vast region stretching from 45°N to 60°N latitude and from the western shores of Hudson Bay to the Pacific Ocean between 1790 and 1812. His 1814 Great Map, compiled from his surveys and those of Alexander Mackenzie, Simon Fraser, George Vancouver and his teacher Philip Turnor, laid the groundwork for development of the Northwest of North America. This paper briefly describes Thompson’s life and remarkable achievements.