The Coteau du Missouri, or Missouri Plateau, is a large plateau that stretches along the eastern side of the valley of the Missouri River in central North Dakota and north-central South Dakota in the United States. In the Canadian provinces of Saskatchewan and Alberta this physiographic region is classified as the uplands Missouri Coteau which is a part of the Great Plains Province or Alberta Plateau Region which extends across the south west corner of the province of Saskatchewan as well as the south east corner of the province of Alberta. Historically, in Canada the area was known as the Palliser's Triangle regarded as an extension of the Great American Desert and unsuitable for agriculture and thus designated by Canadian geographer and explorer John Palliser.