Deer Lake

Deer 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.

The lake's low TSI puts it in oligotrophic territory — the cleanest of the four trophic classes, but also the most vulnerable to nutrient-driven shifts. A maximum depth of 24 ft puts Deer Lake in the middle of Wisconsin's depth distribution. At 66 acres, Deer Lake sits below the Wisconsin median: a small water where shoreline activity has an outsized effect on water quality. Deer Lake ranks 35 of 202 in Vilas County, putting it in the upper tier of locally monitored lakes.

No invasive species are currently listed at Deer 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.