Black Dan Lake

On the LakeGrade rubric, Black Dan Lake pulls an A: clarity at 32.0 ft and phosphorus readings still being added put it in the top bracket for 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. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake's surface area is not consistently recorded across state datasets — physical context remains partial. Among the 52 graded lakes in Sawyer County, Black Dan Lake sits at rank 22, above the county median.

Black Dan Lake has no invasive species recorded in Wisconsin state databases as of 2019, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Black Dan Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.