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. Along the Little Missouri River, the land has eroded to form the Little Missouri Badlands. This is the home of Theodore Roosevelt National Park, named for our most adventurous president, who ranched in the area. If you scraped away North Dakota's grasslands, you'd discover that much of the state is buried under boulders or dust left by glaciers.