From Frozen Sea to Grassland Sea North Dakota remains as flat as it probably was when it was still covered with ancient seas. Put a brick under the bottom left corner of a sheet of plywood, and you will have some idea of what North Dakota is like. It is not perfectly flat, however, thanks largely to Ice Age glaciers. The state s most populated region is the fertile Red River Valley, the bed of an Ice Age lake that runs along the North Dakota-Minnesota border. To the west is the Drift Prairie Region, a glaciated region of rolling hills and rich soils.
Grasses are tall or short, depending on the availability of moisture.
Depressions carved by Ice Age glaciers left thousands of small lakes, sloughs and potholes scattered across North Dakota. Many of these wetlands dried up naturally, while people drained others. Few states boast more wildlife refuges, some scarcely larger than a pothole. Glaciers never covered North Dakota s southwest corner, which is separated from the rest of the state by the Missouri River. This is a drier, more rugged land of short grasses, buttes, bluffs, breaks and badlands.