The Missouri Coteau trends through the state, parallel to and east of the Missouri River. The landscape of the Missouri Coteau formed because glaciers were forced to advance up a steep escarpment before they flowed onto the uplands. As glaciers advanced over the escarpment, sediment from the base of the glacier was forced up to the surface. When the climate moderated and the glaciers stagnated, sediment melting out of the ice accumulated at the surface, insulating the ice so that it took several thousand years to melt completely. As it melted, sediment slumped and slid forming the hummocky topography.
Prairie potholes are most numerous where large-scale glacial stagnation processes dominated.
The topography of the Turtle Mountains and the Prairie Coteau formed in a similar manner to that of the Missouri Coteau. They are erosional bedrock outliers draped with glacial sediments. They, too, are characterized by a hilly, irregular topography with many small ponds and lakes. The Coteau Slope is a rolling to hilly region that contains both glacial and erosional landforms. Unlike the Coteau that bounds its eastern margin, drainage within the Coteau Slope is generally well developed, so that there are comparatively few potholes.