Contained within the 3rd Edition (1957) of the Atlas of Canada is a plate of four maps that shows routes followed by the principal explorers of what is now Canada, prior to Confederation. Rather than attempt to show all the routes on a single map, four maps have been used, each covering a particular period. The first map shows the exploration which took place prior to the formation of the Hudson's Bay Company in 1670. The second map covers the period from 1670 to the treaty of Paris of 1763, when all of Canada became British. The third map terminates in 1795 by which time Mackenzie had made his famous overland journey to the Pacific Ocean and Vancouver had carried out his surveys of the west coast. The fourth map deals with nineteenth century exploration before Confederation.