Little Cosgrove Lake

On the LakeGrade rubric, Little Cosgrove Lake pulls an A: clarity at 28.1 ft and phosphorus readings still being added 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.

Trophically, Little Cosgrove Lake reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. 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. Within the 39 graded lakes of Florence County, Little Cosgrove Lake sits at rank 33, near the bottom of the county list.

No invasive species are currently listed at Little Cosgrove Lake — the lake remains off the Wisconsin infested-waters roster. The state fisheries records do not list documented species for Little Cosgrove Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.