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THOMPSON , DAVID ( 1770 - 1857 ), explorer in British North America ;

b. 30 April 1770 in Westminster , and christened as ‘ Thompson ,’ but his father ( David ) and mother ( Ann ) had borne the surname ‘ Ap Thomas ’ until they moved to London . The father d. when the boy was three. David was educated at the Grey-coat school , until, in 1784 , he was apprenticed to the Hudson Bay Company . After serving for five years as clerk and fur-trader , he came, in 1789-90 , under the influence of the company's surveyor , Philip Turnor , who taught him the elements of astronomy and of triangulation . Surveying and exploration now became his passion, despite the company's disapproval; he mastered several Red Indian dialects, and ‘with Bible and sextant in hand’ (he was also an aggressive ‘teetotaller’) he diligently explored and mapped . Learning from the Indians that there was a short route (shorter than by following the river) to Lake Athabasca , he explored it. In 1797 he transferred his services to the North-Western Company which, though it granted him two years’ leave for exploring , was yet not too willing to see him relegate fur-trading to a secondary place. Meantime, he had traced the Red river and the Assiniboine river to their sources, had followed the Assiniboine to its confluence (in the Winnipeg region) with the Red , had followed the downward course of the Red , and had found the source of the Mississippi . In 1799 he m. Charlotte Small , a girl of mixed Scottish and Indian parentage, who thereafter accompanied him on all his journeys; they had seven sons and six daughters. He explored the course of the S. Lawrence to Lake Superior . In 1807 he crossed the Canadian Rockies ; he discovered the source of the Columbia river , and was the first white man to descend it from source to mouth ( 1811 ), mapping as he went — a journey of over 1,200 miles. He left the North-West Company in 1812 , settling at Montreal in order to construct his great map of the Far West , ‘the basis of every Canadian government map for 100 years, and it still cannot be surpassed for accuracy’ — it is now in the Ontario provincial archives ; in 1816-26 he was on the commission which drew part of the boundary between Canada and the U.S.A. His latter years were years of adversity; he had moved, in 1836 , to Williamstown (Ont.) and opened a shop , but bad debts, reckless generosity, and the business failures of some of his sons, reduced him to penury. He d. at Longueil (on the outskirts of Montreal ) in 1857 , and was buried in Mount Royal cemetery at Montreal . He and his work were completely forgotten till a later geographer , J. B. Tyrrell , retraced his journeys and, in 1916 , published his diaries. There are now monuments to him, on his tomb at Mount Royal , in British Columbia , and in North Dakota ; and the Thompson river in British Columbia was named in compliment after him though not actually explored by him. In 1957 the Dominion government issued a postage stamp to mark the centenary of his death.


  • Dictionary of American Biography (good references);
  • Dictionary of Canadian biography (Toronto, London) ;
  • Maclean's Magazine (Toronto) (Toronto), 9 Nov. 1957 .


Emeritus Professor Robert Thomas Jenkins, C.B.E., D.Litt., Ll.D., F.S.A., (1881-1969), Bangor

Published date: 1959