Fawn Lake

Fawn Lake sits at the top of the Minnesota PCA grading rubric with an A, a mark reached by the cleanest lakes in Minnesota. 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 value of 34 puts Fawn Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. The lake bottoms out at 29 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. The lake is compact at 46 acres, with 1.3 miles of shoreline and little volume to buffer nutrient inputs. Within Cass County's 133 graded waters, Fawn Lake sits at rank 31, near the top of the local distribution.

Fawn Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Fawn Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. No formal public access is documented at Fawn Lake — most use is by shoreline residents and their guests. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.