Black Oak Lake

On the LakeGrade scale Black Oak Lake grades a B, with clarity at 13.9 ft and 29 µg/L of phosphorus placing it above the Wisconsin median. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

Mesotrophic conditions dominate at Black Oak Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. 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. Black Oak Lake ranks 27 of 32 in Langlade County — at the lower end of the locally monitored distribution.

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. 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.