Horseshoe Lake

Horseshoe 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.

A TSI value of 33 puts Horseshoe Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. Horseshoe Lake is unusually deep for Minnesota at 51 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. The lake's 260 acres and 3.8 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Among the 133 graded lakes in Cass County, Horseshoe Lake ranks 2 — in the top quartile locally.

Horseshoe Lake has no invasive species recorded in Minnesota state databases as of 2023, though prevention practices still apply at all access points. Walleye are documented at Horseshoe Lake, one of 12 fish species on record for the lake. A documented public access point at Horseshoe Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.