Canada has approximately 25% of the world’s wetlands. The Hudson Plain alone embraces the bulk of this figure. Some say it is the largest coextensive wetland on the planet.

For the early explorers and fur traders, the Hudson Plain Ecozone acted as a gateway to the interior of central Canada. The area has been associated with the early wars between England and France and with the harshness of pioneering days. Its sense of prominence is largely tied to historical events. Today, it gains much of its recognition from the profile of Polar Bear Provincial Park.

Most of the ecozone lies in northern Ontario but it reaches into Manitoba and, to a lesser extent, Quebec. It occupies about a quarter of Ontario and 4% of Canada, covering 369 000 square kilometres of land and 11 800 square kilometres of water. About 10 000 people live there, representing just 0.04% of Canada’s population. The density is 2.7 people per 100 square kilometres, whereas the Boreal Shield to the south has 155 per 100 square kilometres. Only the Taiga Cordillera and the Arctic Cordillera ecozones have fewer people. Fewer than 10% reside in urban areas.

Overall, the Hudson Plain is poorly drained, flat and dominated by extensive wetlands. As though sculpted by an artist, the greenery of the plains is marked by a series of arcing and evenly-spaced white lines. These belts of raised beaches show the steady progress of rebounding from the weight of the ice sheet that covered the area thousands of years ago. They present striking patterns of successive ridges alternating with bogs and swamps. A cold and long subarctic winter prevails for much of the year. Rising temperatures and melting ice in the summer make fog common on the coast. The short cool summers provide a brief window for the thousands of migratory birds that make their home on the plains.

The wetlands and fog brought early notoriety to this area. For the people in the coastal fortifications established by the Hudson’s Bay Company, the long bitter winters were considered generally insufferable. Summers brought little relief. They summarized the warm season by calling the place an insect-infested landscape of bog and fog.