Lost Lake

Lost Lake sits at the top of the Wisconsin DNR grading rubric with an A, a mark reached by the cleanest lakes in Wisconsin. The two scored sub-grades — clarity and phosphorus — track close together, so neither one is dragging the average down.

The lake sits in the mesotrophic zone — the band where most well-managed Wisconsin lakes fall. Lost Lake reaches 45 ft at its deepest point — typical for Wisconsin mid-sized lakes, with seasonal stratification but limited cold-water refuge. Lost Lake is small — 84 acres alongside partial shoreline records — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Lost Lake ranks 10 of 39 in Florence County — solidly in the upper half of the local distribution.

No invasive species are currently listed at Lost Lake — the lake remains off the Wisconsin infested-waters roster. Bass fishing is part of the appeal: the species list runs to 2, anchored by largemouth and/or smallmouth bass. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.