A Lake Made of Ice: The Glacial Origins of Geneva Lake
Near Lake Geneva, Wisconsin
Geneva Lake did not exist before the last ice age. It was carved by a lobe of the Laurentide Ice Sheet, the immense glacial system that covered much of North America during the Pleistocene. As the glacier retreated roughly ten thousand years ago, it left a basin scooped from the bedrock, and meltwater filled it.
The specific ice mass that shaped this basin, the Delavan Lobe, also created Delavan Lake to the west and deposited the glacial ridge that separates the two. The result is a lake with unusual characteristics for the Midwest. Geneva Lake reaches a maximum depth of one hundred thirty-five feet in its western basin, making it one of the deepest lakes in Wisconsin.
The water is exceptionally clear, kept so by the depth itself and by the absence of major river inflow carrying silt. The lake's outline is irregular, with the narrow passage called The Narrows dividing the eastern and western sections. The lake surface covers more than five thousand acres and drains southward through White River toward the Fox River system.
That depth and clarity are what made the lake exceptional as a resort destination. You could see the bottom in places. The water stayed cold even in midsummer.
The fishing was excellent. Those qualities were the original draw, before the mansions and the festivals, and they persist today.
