Black Oak Lake

The LakeGrade rubric puts Black Oak Lake at a C: clarity at 4.3 ft, 29 µg/L of phosphorus, and a TSI of 54 signal an intermediate trophic state. Clarity is the limiting factor — phosphorus is reasonable but suspended particles or algal cells keep water transparency below Wisconsin norms.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. A maximum depth of 34 ft puts Black Oak Lake in the middle of Wisconsin's depth distribution. At 56 acres, Black Oak Lake sits below the Wisconsin median: a small water where shoreline activity has an outsized effect on water quality. Within Langlade County's 32 graded lakes, Black Oak Lake ranks 18 — below the local median, though not at the bottom.

No invasive species are currently listed at Black Oak Lake — the lake remains off the Wisconsin infested-waters roster. Bass fishing is part of the appeal: the species list runs to 3, anchored by largemouth and/or smallmouth bass. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.