Hudson Plains

The Hudson Plains Ecozone, as defined by the Commission for Environmental Cooperation (CEC), is a sparsely populated Canadian subarctic ecozone extending from the western coast of Quebec to the coast of Manitoba, encompassing all coastal areas of James Bay and those of southern Hudson Bay, stretching to about 50°N latitude. It includes the largest continuous wetland in the world. It covers nearly a quarter of Ontario's landmass, and 3.6% of Canada's total area, totalling approximately 369,000 square kilometres of land and 11,800 square kilometres of water. Its historical prominence is due to the harshness endured by pioneer explorers who established fortifications for Hudson's Bay Company, and as a result of regional wars between France and Britain. Today, it is primarily noted for the well-known Polar Bear Provincial Park, and to a lesser extent Wapusk National Park, as well as its vast wetlands which are used by migratory birds.

The Palaeozoic and Proterozoic sedimentary deposits overlaying the bedrock have formed into a wide and level plain characterised by raised beaches and river deltas, with an elevation rarely exceeding 120 m. The relatively flat land slopes gently toward the two bays, which act as a drainage basin for the region. However, the relatively poor drainage system has spurred the natural development of numerous wetlands. It is encircled by the Canadian Shield, with which it overlaps in a few areas to the east and west.

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