Duck Lake

On the scoring rubric Duck Lake grades a D: clarity at 4.0 ft and phosphorus readings still being added keep it in the lower bracket for Vilas County. 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.

A TSI in the eutrophic range signals a lake doing what nutrient-loaded waters do — supporting an active algal community at the cost of clear water. Duck Lake reaches 20 ft at its deepest point — typical for Wisconsin mid-sized lakes, with seasonal stratification but limited cold-water refuge. At 106 acres, Duck Lake fits the Wisconsin median for monitored lakes, with partial shoreline records. Duck Lake ranks 170 of 191 in Vilas County — at the lower end of the locally monitored distribution.

Eurasian watermilfoil has been documented at Duck Lake, requiring shoreline management to keep dense mats from crowding native vegetation. The fishery includes walleye alongside the lake's other 6 documented species — a notable draw for Wisconsin anglers. 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.