Loon Lake

Loon Lake earns a C — middle-of-the-pack water quality, with one or two parameters dragging the average down from a stronger grade. Secchi readings are the weakest of the scored parameters, suggesting suspended sediment or algal biomass dominates the optical signal.

At a TSI of 50, Loon Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. A maximum depth of 22 ft puts Loon Lake in the middle of Wisconsin's depth distribution. At 327 acres, Loon Lake fits the Wisconsin median for monitored lakes, with partial shoreline records. Within Shawano County's 27 graded lakes, Loon Lake ranks 17 — below the local median, though not at the bottom.

Eurasian watermilfoil is established at Loon Lake, which can dampen recreational access and pressure the native plant community. The fishery includes walleye among the lake's 4 documented species — a notable draw for Wisconsin anglers. 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.