This ecoregion stretches northwestward from the International Boundary with the United States to Dauphin Lake. It is one of the warmest and most humid regions in the Canadian prairies. The mean annual temperature ranges from 2°C in the north to over 3°C along the Canada-United States border. The mean summer temperature is 16°C and the mean winter temperature is -12.5°C. The mean annual precipitation ranges 450-700 mm.

The ecoregion is transitional between areas of boreal forest to the north and the aspen parkland of the southwest. It is a mosaic of trembling aspen/oak groves and rough fescue grasslands. Trembling aspen and shrubs occur on moist sites, and bur oak and grass species occupy increasingly drier sites on loamy to clayey, Black Chernozemic soils. Poorly drained, Gleysolic soils support willow and sedge communities. Lower and smoother than the Saskatchewan Plain to the west (Aspen Parkland ecoregion), the surface of the plain has an elevation ranging from about 410 m asl near the Manitoba Escarpment to 218 m asl at Lake Winnipeg. This low-relief ecoregion, underlain by limestone bedrock, is covered by extremely calcareous, broadly ridged glacial till in its northern half and by smooth, level, lacustrine sands, silts, and clays in its southern half. Wildlife includes significant waterfowl, as well as white-tailed deer, coyote, rabbit, and ground squirrel.

Its growing season length, available heat, and precipitation permit the production of corn, spring wheat, and other cereal grains by dryland continuous cropping methods. Oilseeds, hay, and livestock production are more prevalent in the northern section owing to topography and stoniness limitations. Hunting and water-oriented recreation are additional significant uses of land. The major communities include Winnipeg, Portage la Prairie, Emerson, and Dauphin. The population of the ecoregion is approximately 782,100.