Green Lake...Wisconsin's Deepest Inland Lake

Located in beautiful Green Lake County, Wisconsin, Green Lake had its origin in a valley formed by a preglacial river. Glaciation deposited terminal moraines across the western end of the valley (along present-day Highway 73), which impounded the water and created the lake 12,000-23,000 years ago.

The Green Lake watershed encompasses approximately 57,000 acres. Silver Creek is the main tributary. Eight small streams also drain into the lake. The lake's outlet is the Puchyan River, which drains into the Fox River, and ultimately into Lake Michigan at Green Bay. A dam was constructed at the outlet in 1846 and increased the water level 5 feet by 1890.

Today, gates in the dam operated by the city of Green Lake control the water level. A regulation of the Department of Natural Resources specifies the maximum levels to be maintained in summer and in winter.

The sources of Green Lake's water, in approximate percentages, are: precipitation, 51%; surface water, 41%; ground water, 8%.

Some Lake Facts