Halfmoon Lake

Halfmoon Lake sits at the top of the Wisconsin DNR grading rubric with an A, a mark reached by the cleanest lakes in Wisconsin. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

Trophically, Halfmoon Lake reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. Halfmoon Lake is a shallow lake at 14 ft maximum depth, which means it warms quickly, mixes constantly, and amplifies nutrient inputs. The lake's 102 acres and partial shoreline records put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Among the 21 graded lakes in Lincoln County, Halfmoon Lake sits at rank 10, above the county median.

No invasive species are currently listed at Halfmoon Lake — the lake remains off the Wisconsin infested-waters roster. Bass fishing is part of the appeal: the species list runs to 3, anchored by largemouth and/or smallmouth bass. Public access is available — the lake is on the Wisconsin DNR public-access list. 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.