St. Louis Bay Lake

St. Louis Bay Lake pulls a D on the LakeGrade rubric — phosphorus loading and limited clarity hold it below the Wisconsin average. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

At a TSI of 69, St. Louis Bay Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. 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. St. Louis Bay Lake ranks 34 of 44 in Douglas County — at the lower end of the locally monitored distribution.

No invasive species are currently listed at St. Louis Bay Lake — the lake remains off the Wisconsin infested-waters roster. The state fisheries records do not list documented species for St. Louis Bay 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.