Exploration in the period 1731 to 1757 was dominated by the rapid thrust of French exploration into the western interior of Canada, particularly by Pierre Gaultier de la Vérendrye and his five sons who made nine expeditions between 1731 to 1743. As well, the map shows the exploration routes of other explorers sponsored either by New France or by England: Mallet (1739), De Niverville (1751), Henday (1754 to 1755) and Smith and Waggoner (1756 to 1757). The map also shows the extent of territory known to Europeans and the navigation of all exploration routes in the period 1651 to 1760. The historical names found on the map are derived from contemporaneous maps and written documents of the period.