North Dakota is sometimes disparagingly labeled “flyover country”—perceived of as a monotonous, relentlessly flat, sparsely populated chunk of the central United States. This is a significant misconception, though the state does indeed harbor one of the lowest population densities in the country. From the birch woodlands of the Turtle Mountains to the bluffs of the Missouri River, and from the bird-haunted pothole lakes of the Coteau des Prairies to the rugged badlands of the far west, the land features of North Dakota help to support a number of diverse ecosystems.
Eastern North Dakota falls within the Central Lowlands, a massive interior basin bordering the Canadian Shield to the north, the Appalachians to the East, the Ouachita-Ozark plateaus and Gulf Coastal Plain to the south, and the Great Plains to the west. The Plains occupy the western portion of North Dakota—specifically that portion known as the Missouri Plateau, which has been heavily dissected by the Missouri River and its tributaries.
Glacial Lake Agassiz
Lake Agassiz no longer exists, but its continuing influence on the eastern North Dakota landscape—as well as that of a broad contiguous region—is profound. The lake was one of the great glacial water-bodies of the last Ice Age. Consisting of meltwater pooled at the margin of the massive continental glacier, the lake at one point covered over 120,000 square miles, stretched for some 700 miles and was 400 feet deep. This encompassed substantial portions of North Dakota, northwestern Minnesota and particularly huge acreage in Manitoba and Ontario. As the glacier retreated, this massive lake drained over time via a variety of outflows, most prominently Hudson Bay. Today, the strikingly flat floor of the ghost lake, underlain by lacustrine and glacial sediments, is an important land feature and supports intensive agriculture. In North Dakota, wheat, potatoes, sugar beets and other crops are grown in this old lakebed.
The Coteau des Prairies
The Coteau des Prairies or Missouri Coteau is one of the heraldic land features of the Central Lowlands-Great Plains frontier, a great rolling upland that sprawls across the Dakotas, Minnesota and Iowa. It helps define the western escarpment bounding Glacial Lake Agassiz, which extends in broken fashion north into Canada. Ridden with pothole lakes where a lobe of the Wisconsin ice sheet persisted and roughly melted, the Coteau des Prairies supports thousands of migratory waterfowl, as well as agriculture and grazing land.
Much of North Dakota is unforested, whether because of climatic influence (its portion of the Great Plains) or clearing for agriculture. But a few isolated uplands support rich woods reminiscent of the mixed hardwood and boreal forests to the north and east. These include the Turtle Mountains and Pembina Escarpment fast against the Canada border, with their woodlands of oak, aspen, birch, ash, and elm. Moose, black bear, and other animals widespread in timbered country of the Upper Midwest and Canadian Shield are found here. The Northern Black Prairie, strung about the Turtle Mountains and Pembina Escarpment, also features scattered woods, marking an ecological frontier of prairie and boreal species.
Rolling mixed-grass prairie once defined much of North Dakota’s portion of the Missouri Plateau. The most striking land features here are so-called badlands: tracts of heavily eroded, lightly vegetated sedimentary formations common to semi-arid and arid landscapes. An extensive example are the badlands of the Little Missouri River and its tributaries, protected in Theodore Roosevelt National Park. Compared with the barren, knife-edged pinnacles of South Dakota’s White River Badlands, these North Dakota land features are more subdued and comparatively lush, supporting rich grasslands, savannas of Rocky Mountain juniper and gallery forests of cottonwood and ash. They are very rich in wildlife. Ungulates include bison, pronghorn, elk, mule deer and feral horses and longhorn cattle, while coyotes, pumas, bobcats and badgers prowl scrub and prairie.
(1) Northern Prairie Wildlife Research Center: Ecoregions of North Dakota & South Dakota – North Dakota Ecoregion Map
(2) US EPA: Ecoregions of North Dakota & South Dakota
(3) Minnesota River Basin Data Center: Minnesota River Valley Formation
(4) Bluemle, John. North Dakota Notes #15: North Dakota's Mountainous Areas. North Dakota Geological Survey. 2002.
(5) Henry, James A. & Joann Mossa. Natural Landscapes of the United States. 1995.