Glacial Lake Wisconsin

Glacial Lake Wisconsin was a significant feature of the glacial history and landscape of Wisconsin and North America. It was a large lake that formed about 18,000 years ago when a glacier blocked the outlet of the Wisconsin River around the Baraboo Hills. The lake covered an area of almost 44,000 square miles and reached a depth of 160 feet. It lasted for about 4,000 years until the glacier retreated and the lake drained catastrophically through the south end, carving the Dells of the Wisconsin River. The lake left behind a flat sandy plain that is now part of the Central Sand Plains and Central Sand Hills ecological landscapes of Wisconsin. The lake also influenced the formation and distribution of the glacial features that are part of the Ice Age National Scientific Reserve, such as moraines, drumlins, eskers, kames, and kettles. The lake also provided habitat for various plants and animals that adapted to the cold and wet conditions. Glacial Lake Wisconsin was one of the largest and longest-lasting proglacial lakes in North America and had a major impact on the geology, ecology, and culture of the region.