
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. This physiographic region of Saskatchewan and Alberta is classifed as the uplands Missouri Coteau which is a part of the Great Plains Province or Alberta Plateau Region which extends across the south east corner of the province of
Saskatchewan as well as the south west corner of the province of
Alberta.
[1]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.
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.
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,
Bad, and
White rivers.
To the east of the plateau, the lowland valley of the
James River was formed by the lobe of the most recent
ice age, separating the plateau from the
Coteau des Prairies to the east.
Agriculturally the plateau is a grain and livestock region.
See also
★
Coteau des Prairies
★
Geography of Saskatchewan
★
Cypress Hills Interprovincial Park
★
Cypress Hills
★
List of highest points of Canadian provinces and territories
External links
★
South Dakota's Physiographic Regions