Lake Circle

Lake Circle was a glacial lake in eastern Montana during the late Pleistocene, formed when meltwater from the retreating Laurentide Ice Sheet pooled along the Redwater River in a basin enclosed by a preglacial valley and the ice margin. Its remnants are linked to a broad abandoned valley southwest of Nickwall that extends north from Redwater Creek to the Missouri River. The valley’s wide, poorly drained floor, flat uplands, and contrast with nearby V-shaped coulees show sedimentation from the lake rather than normal stream erosion. The lake belongs to the late Wisconsin glacial episode, when the Havre lobe dammed the ancestral Missouri River.

Montana · United States