White Mound Lake

White Mound Lake sits at the top of the Wisconsin DNR grading rubric with an A, a mark reached by the cleanest lakes in Wisconsin. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

The lake sits in the mesotrophic zone — the band where most well-managed Wisconsin lakes fall. White Mound Lake reaches 16 ft at its deepest point — typical for Wisconsin mid-sized lakes, with seasonal stratification but limited cold-water refuge. At 93 acres, White Mound Lake sits below the Wisconsin median: a small water where shoreline activity has an outsized effect on water quality. White Mound Lake ranks 4 of 11 in Sauk County — solidly in the upper half of the local distribution.

Eurasian watermilfoil is established at White Mound Lake, which can dampen recreational access and pressure the native plant community. Bass fishing is part of the appeal: the species list runs to 3, anchored by largemouth and/or smallmouth bass. A documented public access point at White Mound Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.