Shemahgun Lake

Shemahgun Lake sits at the top of the Minnesota PCA grading rubric with an A, a mark reached by the cleanest lakes in Minnesota. 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's surface area is not consistently recorded across state datasets — physical context remains partial. Shemahgun Lake ranks 16 of 86 in Beltrami County, putting it in the upper tier of locally monitored lakes.

No invasive species are currently listed at Shemahgun Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Shemahgun Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.