Gile Flowage Lake

Gile Flowage Lake sits at a C on the grading scale — not impaired, not pristine, with summer measurements that vary year to year. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

At a TSI of 54, Gile Flowage 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. With 3,317 acres of surface and partial shoreline records, Gile Flowage Lake is a large water by Wisconsin standards — recreational pressure is spread across a long shoreline. Gile Flowage Lake ranks 28 of 33 in Iron County — at the lower end of the locally monitored distribution.

Gile Flowage Lake has no invasive species recorded in Wisconsin state databases as of 2026, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Gile Flowage 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.