Lake Dorothy

Lake Dorothy sits at the top of the Wisconsin DNR grading rubric with an A, a mark reached by the cleanest lakes in Wisconsin. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

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. Lake Dorothy reaches 26 ft at its deepest point — typical for Wisconsin mid-sized lakes, with seasonal stratification but limited cold-water refuge. The lake is compact at 21 acres, with partial shoreline records and little volume to buffer nutrient inputs. Lake Dorothy sits at rank 24 of 34 in Iron County, in the lower half of the local distribution.

Lake Dorothy has no invasive species recorded in Wisconsin state databases as of 2022, though prevention practices still apply at all access points. The fishery is bass-led, with 3 documented species across the lake's records. 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.