America. Lake Winnipeg and other lakes in Manitoba are remnants of the immense Agassiz, as are the province’s wetlands of prairie potholes, ponds, and cattail marshes.

This ecozone is generally dry because the Rocky Mountains block airstreams bringing moisture from the Pacific. Southwestern Saskatchewan and southeastern Alberta are the driest areas, with a mean annual precipitation of 250 millimetres; the wettest area is in the east, in the Manitoba Lowlands, with just under 700 millimetres. The dryness is also exacerbated by what Saskatchewan author W.O. Mitchell called the “unfailing visitation of wind” across the generally flat and open landscape. The short, warm summers produce mean annual temperatures of between 14°C and 16°C, and the temperatures of the long and cold, but sunny winters, range from -12.5°C to -8°C. Winnipeg is even colder. With winter temperatures averaging as low as -24°C in January, Manitoba’s capital is

Canada’s coldest city. But it is also the sunniest, with over 2300 hours of sun annually, and it boasts some of the country’s bluest skies.

Human beings, beginning with the ancestors of today’s Assiniboine, Blackfoot, and Cree peoples, have lived on the Prairies for an estimated 18,000 years. Now, almost four million people live in this ecozone, about 80 percent of them in urban areas, such as the cities of Edmonton, Calgary, Regina, Saskatoon, and Winnipeg. While most of the zone is used for agriculture (wheat, dairy, and cattle farming), under 10 percent of the population is actually involved in this sector. Most of the population work in the service and mining industries, and in oil and gas production.