Canada occupies the northern half of the North American continent. Among its dominant physical features are abundant rivers and lakes which have had a significant effect on the history of the country. Waterways provided the main avenues of transportation and access to the interior for indigenous peoples and for European explorers and traders. The map indicates four main systems of waterways draining the interior of the country. The Atlantic drainage system, dominated by the Great Lakes and the St. Lawrence River, was the most important waterway system in the history of the Canadian fur trade, constituting a superb inland route to the head of Lake Superior. The Hudson Bay basin was the second drainage system exploited by fur traders. It eventually provided access to much of the Canadian Shield, as well as to the prairie and parkland regions of the Great Plains. The arctic basin, dominated by the Mackenzie River, proved to be the source of the most luxurious beaver pelts, but was not exploited until late in the eighteenth century. The rivers of the Pacific basin pass through successive ranges of mountains and are marked by deep canyons and frequent falls and rapids. Except for the Columbia and the Lower Fraser, these rivers were not suited to the purposes of the fur trade and the region was the final western frontier of the trade, not exploited until the early nineteenth century.
