thumb|right|300px|map of palliser's triangle. canadian section of the coteau du missouri 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. the terrain of the missouri coteau features low hummocky, undulating, rolling hills, potholes, and grasslands. thumb|left|missouri plateau geologically the plateau is part of the extended plateau of the great plains in the dakotas, and is separated from the main plateau to the west by the missouri river trench. the plateau is underlain by pierre shale covered with hardened deposits from repeated glaciations. the plateau also contains deposits of lignite, mirabilite (sodium sulfate), and bentonite. while subjected to continental glaciation, it was north and west of the driftless area, an area which escaped glaciation. the plateau is poorly drained and is interspersed with glacial kettle lakes. it is transversed by several broad sags marking the ancient stream valleys of the eastern continuations of the grand, moreau, cheyenne, cheyenne river, [[bad river (south dakota)|ba
Great_Plains Landforms_of_Alberta Landforms_of_North_Dakota Landforms_of_Saskatchewan Landforms_of_South_Dakota Plateaus_of_the_United_States Regions_of_North_Dakota