Frog Lake

On the LakeGrade rubric, Frog Lake pulls an A: clarity at 31.2 ft and 16 µg/L of phosphorus put it in the top bracket for Wisconsin. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

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 39 graded lakes in Florence County, Frog Lake sits at rank 18, above the county median.

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