File:Map of Western British North America (David Thompson 1813-1814).jpg

Map of Western British North America (David Thompson 1813-1814) David Thompson is probably most widely known for the map he prepared in 1813-1814 for the North West Company of the region extending from Sault Ste. Marie to the Pacific Ocean, and from the 45th to 60th parallels. That particular map does not appear to have survived, but there is a similar map by him in the possession of the Public Archives of Ontario. According to professor V.G. Hopwood, Thompson regarded the map or maps he drew in 1813-1814 as preliminary drafts, and this is what they appear to be when one considers that most of the names are written, not printed. Nevertheless the map which survives is of monumental importance. In preparing it Thompson gathered together the data he had collected on his thousands of miles of surveys in the West, a collection of primary source material surpassing that of any other scientific explorer, and combined it with information from other sources. Thompson was the first person to map many of the features of present southern Manitoba and the region near the headwaters of the Mississippi river. It is unfortunate that Thompson was not successful in his many attempts to get the map published during his lifetime. This part of the map shows that the rivers surveyed by Thompson, such as the Stone Indian (Assiniboine) and Dauphin, are drawn with reasonable accuracy but this is not true of the details in those regions not actually surveyed by him. An example is the outlines of Lakes Manitoba and Dauphin. Part of the line of the Manitoba Escarpment can be clearly seen in Thompson’s early attempt at relief shading. The original map in the Public Archives of Ontario is so badly faded and cracked that it cannot be photographed legibly. Hence this copy is made from a re-drawn map in the Champlain Society’s edition of Thompson’s Narrative, edited by J.B. Tyrrell. On the original the relief is drawn using hachures which are up to half an inch long, and the hills do not have the soft rounded impression of the Tyrrell copy. Also, the Tyrrell copy is missing some relief features, for example, Boss Hill, a few names of rivers such as “Bad Water Rivulet” and “Rat Brook”, and even some of the names of trading posts, such as the N.W. Co. post junction of the Rat and the Red rivers. It should be pointed out that what look like correction line jogs on the Tyrrell copy are actually places where the joins of the different sections of the map do not match. On the other hand, to correct the balance, one must add that the Tyrrell copy has place names which by now have faded on the original, and can be best be located by using the Tyrrell map as a guide. (Warkentin and Ruggles. Historical Atlas of Manitoba. map 56, p. 144)

Map of the North-West Territory of the Province of Canada from actual survey during the years 1782-1812. This map, made for the North West Company in 1813 and 1814 and delivered to the Honorable William McGillivray, then Agent, embraces the region lying between 45 and 60 degrees North Latitude and 84 and 124 West Longitude comprising the surveys and discoveries of 20 years, namely the discovery and survey of the Oregon Territory to the Pacific Ocean, the survey of the Athabaska Lake, Slave River and Lake from which flows Mackenzies River to the Arctic Sea by Mr. Phillip Turner the route of Sir Alexander Mackenzie in 1792 [sic] down part of Frasers River together with the survey of this River to the Pacific Ocean by the late John Stewart of the North West Company, by David Thompson Astronomer and Surveyor Sgd. David Thompson. This is a reproduction from J.B. Tyrrell, ed. David Thompson’s Narrative of His Explorations in Western America 1784-1812. Toronto: The Champlain Society, 1916.