Situated in the geographical center of North America, North Dakota is subject to the extremes of a continental climate. Semiarid conditions prevail in the western half of the state, but in the east an average annual rainfall of 22 in. (55 cm), much of it falling in the crop-growing spring and summer months, enables the rich soil to yield abundantly. North Dakota is one of the most rural states in the nation; the cities and towns supply the needs of neighboring farms, and industry is largely devoted to the processing of agricultural products.
The eastern half of the state is in the central lowlands, a belt of black earth covered in spring by the soft green of sprouting grain and later by the bronze of flowering wheat or the blue of flax. Along the banks of the Red River lies a wedge of land, c.40 mi (60 km) wide at the Canadian border and tapering to 10 mi (16 km) in the south, that is the floor of the former glacial Lake Agassiz. Treeless, except along the rivers, and without surface rocks, this flat land was transformed into the bonanza wheat fields of the 1870s and 80s, with farms ranging in size from 3,000 to 65,000 acres (1,200–26,000 hectares). Today the average farm in the Red River valley is about 450 acres (180 hectares); the state average is about 1,300 acres (525 hectares). Its major crop, wheat, is varied with such crops as flax and seed potatoes.
To the west of the valley a series of escarpments rises some 300 ft (91 m) to meet the drift prairies, where rolling hills, scattered lakes, and occasional moraines form a pleasant and fertile countryside. The productivity of the soil makes North Dakota a leader in wheat (ranking second in the nation), barley, sugar beets, oats, soybeans, and sunflowers. In income earned, however, cattle and cattle products exceed all the crops except wheat.
In the western part of the state a combination of unfavorable topography and scant rainfall precludes intensive cultivation except in the river valleys. An area some 50 mi (80 km) E of the Missouri River is a farm and grazing belt, separated from the drift prairies by the Missouri escarpment. Westward from the Missouri rolls an irregular plateau, covered with short prairie grasses and cut by deep gullies. Where wind and rain have eroded the hillsides there are unusual formations of sand and clay, glowing in yellows, reds, browns, and grays. Along the Little Missouri this section is called the Badlands, so named because the region (once described as "hell with the fires out") was difficult to traverse in early days. Situated there, where from 1883 to 1886 the young Theodore Roosevelt spent part of each year ranching, are the three units of the Theodore Roosevelt National Park. Bismarck, on the eastern bank of the Missouri River, is the capital and Fargo is the largest city.