Horseshoe Lake

Horseshoe Lake earns a D — measurements through 2024 show persistent nutrient pressure that limits clarity through the summer.

At a TSI of 59, Horseshoe Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. Horseshoe Lake is a shallow lake at 12 ft maximum depth, which means it warms quickly, mixes constantly, and amplifies nutrient inputs. The lake's 240 acres and 3.7 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Within Aitkin County's 53 graded lakes, Horseshoe Lake ranks 36 — below the local median, though not at the bottom.

Horseshoe Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. The fishery includes walleye among the lake's 12 documented species — a notable draw for Minnesota anglers. The lake lacks a documented public access point, so visitor use is limited. Ice-out has been recorded 8 times at Horseshoe Lake, with a median around Apr 15. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.