Pembina Escarpment

The Pembina Escarpment is a scarp that runs from South Dakota to Manitoba, and forms the western wall of the Red River Valley.

As the ice sheet began to melt and recede, the meltwaters filled the ancestral Red River Valley to create Lake Agassiz.

[7] Both the US and Canada consider Turtle Mountain to be a sibling ecodistrict with the Pembina Escarpment, as both countries place both areas within the same larger ecoregions.

Before the Europeans settled in this region, the slopes and peaks of the escarpment were largely covered by a deciduous forest of burr oak and trembling aspen.

The areas along rivers and creeks with more moisture had Manitoba maple, green ash, red osier dogwood and willows.

Lockhart Phase of Lake Agassiz approximately 11,500 years ago when the Pembina Escarpment was formed. The area north of the orange line was the Laurentide Ice Sheet .