Anderson Lake

Anderson 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's low TSI puts it in oligotrophic territory — the cleanest of the four trophic classes, but also the most vulnerable to nutrient-driven shifts. Anderson Lake reaches 40 ft at its deepest point — typical for Wisconsin mid-sized lakes, with seasonal stratification but limited cold-water refuge. At 177 acres, Anderson Lake fits the Wisconsin median for monitored lakes, with partial shoreline records. Within Oconto County's 66 graded waters, Anderson Lake sits at rank 12, near the top of the local distribution.

Eurasian watermilfoil has been documented at Anderson Lake, requiring shoreline management to keep dense mats from crowding native vegetation. Walleye are documented at Anderson Lake, one of 5 fish species on record for the lake. Public access is available — the lake is on the Wisconsin DNR public-access list. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.