Easternmost of the Prairie Provinces, Manitoba is bounded on the N by Nunavut (with a northeast shoreline on Hudson Bay), on the E by Ontario, on the S by Minnesota and North Dakota, and on the W by Saskatchewan. The south and central part of Manitoba was once covered by Pleistocene Lake Agassiz; as its waters receded into Hudson Bay, it left behind numerous lakes (the largest being Winnipeg, Manitoba, and Winnipegosis) and rivers (including the Nelson, Churchill, and Hayes) that flow northeast into the bay. In some places underlying rock formations were swept bare; in others they were covered with rich deposits of black loam. An expanse of almost uninhabited tundra surrounds the port of Churchill.
Extending south from Churchill and east from Lake Winnipeg, the topography is that of the Canadian Shield; limited areas have been cleared for general farming and dairying, and mineral and timber resources have been partly developed. Southern Manitoba is dominated by lakes, with Lake Winnipeg paralleled in the west by Winnipegosis and Manitoba. Most of the province's population is concentrated in the river valleys south of these lakes. To the west and north of the Red River valley, the land rises in an escarpment extending into the plateaus of the Pembina, Turtle, Riding, Duck, and Porcupine mountains. Much of this heavily forested area has been set off as reserves, and the Riding Mt. area is a national park.
Winnipeg is the capital and the largest city, accounting for over half of the province's population in its metropolitan area. Other important cities are Brandon, Thompson, Portage la Prairie, and Selkirk.