Ucil Lake

Ucil Lake sits at the top of the Wisconsin DNR grading rubric with an A, a mark reached by the cleanest lakes in Wisconsin. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

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 is compact at 78 acres, with partial shoreline records and little volume to buffer nutrient inputs. Within Oconto County's 66 graded lakes, Ucil Lake ranks 37 — below the local median, though not at the bottom.

Eurasian watermilfoil is established at Ucil Lake, which can dampen recreational access and pressure the native plant community. The fishery is bass-led, with 3 documented species across the lake's records. A documented public access point at Ucil Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. 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.