The Canadian Shield is a large geographical area that covers eastern and central Canada and parts of the northern United States. Comprised of bare rock, including granite and gneiss, the Canadian Shield dates back to the Precambrian Era (between 4.5 billion and 540 million years ago.) Several bodies of waters fall within the borders of the Shield, including the St. Lawrence River, the Great Lakes, the Hudson Bay and Lake Athabasca.
St. Lawrence River
In the Thousand Islands vicinity of the St. Lawrence River, the Canadian Shield crosses the foothills of this region between Southern Ontario and northern New York. High walls of granite formations are notable in this region, given the glacial carving from millions of years past. Highways are bordered by the high walls of granite, and the St. Lawrence River continues to provide a waterway for shipping raw materials such as stone, iron ore and other resources. Lake Superior meets with the St. Lawrence River in the lower river basin, and the upper basin begins in the northern reaches of Quebec.
The Great Lakes
The Canadian Shield covers a majority of the northern and southeast province of Ontario, which include Lake Huron, Ontario and portions of Lake Superior. The basins and paths, including small freshwater rivers and creeks connected to the Great Lakes, were formed by the Shield. In the 1800’s, Canadian fur traders and trappers used the Great lakes to transport their goods south into the United States.
The Hudson Bay
The Canadian Shield completely surrounds the Hudson Bay in the province of Quebec, forming a horseshoe pattern around the expansive lake. The Hudson Bay was used to transport fur, minerals and timber. Given that the Hudson Bay freezes for up to six months per year, transportation was limited and seasonal. Rock formations are found along the banks of the Hudson Bay, which were formed by glacial activity.
Several freshwater lakes in Canada are within the Canadian Shield, including the 240-mile long Lake Athabasca. Located in the provinces of Alberta and Saskatchewan, this lake has the largest concentration of sand dunes in North America. Fishing is popular at Lake Athabasca, with species including Lake trout, Walleye and Northern Pike. Granite from the Canadian Shield forms the northern shores of Lake Athabasca.