Coteau (as a large-scale landscape feature) is chiefly an American usage of a French word for a hillside or the terraced slope of a vineyard. Americans use the word, borrowed from French Canadian frontiersmen, to name the steep ridge above and between lower elevations to either side or to describe hilly ground overlooking a plain. The name also is given in Louisiana to a substantial mound of solid ground in a swamp or marsh. The Missouri Coteau/Coteau du Missouri is a narrow plateau beginning in the northwest corner of North Dakota. Its western escarpment forms the bluffs of the Missouri River. The Prairie Coteau/Coteau des Prairies is an extensive plateau in South Dakota and Minnesota that was processed into its current form at the end of the last North American glaciation. The Prairie Coteau is a hilly, hummocky complex of moraines, basins, and pothole wetlands. Many of these features were formed by dead ice.

D. J. Waldie