South Bay Lake

On the LakeGrade scale South Bay Lake grades a B, with clarity at 12.0 ft and phosphorus readings still being added placing it above the Wisconsin median. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

The lake sits in the mesotrophic zone — the band where most well-managed Wisconsin lakes fall. A maximum depth of 46 ft puts South Bay Lake in the middle of Wisconsin's depth distribution. South Bay Lake covers 839 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. South Bay Lake ranks 13 of 34 in Forest County — solidly in the upper half of the local distribution.

South Bay Lake has at least one documented invasive species (Banded Mystery Snail), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. Walleye are documented at South Bay Lake, one of 5 fish species on record for the lake. A documented public access point at South Bay Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.