Geology of the Area

Hills of North Dakota

NPS Staff / Carrie Maddox

Quick Facts

Location:

Knife River Indian Villages National Historic Site

Significance:

Geology of the area

The Missouri River is the natural divide of two regions in North Dakota, the Drift Prairie, on the east side, and the Missouri Plateau, on the west side. The eastern part of the Missouri Plateau is called the Missouri Coteau (koe-TOE). “Coteau” is a French word, meaning “little hill.” The hills are made of the soil and rocks that were deposited when the last glacier melted. 

According to the North Dakota State Historical Society, “When the last glacier advanced into North Dakota, it did not cover the southwestern part of the state. For that reason, this land in the Missouri Plateau was not scraped and flattened out as the rest of the state. The hill features in the Missouri Plateau were shaped mainly by erosion, such as wind and rushing water. Much of the Missouri Plateau has small hills.”