Proglacial Lakes of Minnesota - Glacial Lake Duluth

Glacial Lake Duluth

Glacial Lake Duluth is the name given to the largest of a series of named lakes or lake stages occupying parts of the Lake Superior basin. As its current outlet to the east was blocked by the Superior Lobe of the ice sheet, Lake Duluth drained through two outlets which crossed the present Laurentian Divide to the valley of the Saint Croix River and the Mississippi. One outlet was a route from the western part of the lake through the Nemadji River basin and down the present Moose and Kettle Rivers; the other was via the modern Bois Brule River to the Saint Croix. At its peak, Lake Duluth was 148 meters higher than Superior's present level. When the glacier retreated the lake was able to drain to the east.