Loon Lake

Loon Lake sits at the top of the Wisconsin DNR grading rubric with an A, a mark reached by the cleanest lakes in 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.

A TSI near 42 places Loon Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. 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 18 — 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 alongside the lake's other 4 documented species — a notable draw for Wisconsin anglers. A documented public access point at Loon 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.