Andrusia Lake

Andrusia 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.

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. Andrusia Lake is unusually deep for Minnesota at 60 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. With 1,596 acres of surface and 10.3 miles of shoreline, Andrusia Lake is a large water by Minnesota standards — recreational pressure is spread across a long shoreline. Andrusia Lake ranks 7 of 86 in Beltrami County, putting it in the upper tier of locally monitored lakes.

Zebra mussel presence at Andrusia Lake means the lake's clarity numbers carry an asterisk — filtered water is not the same as nutrient-poor water. Andrusia Lake's fishery is anchored by muskellunge, with 21 documented species in total — a destination water for muskie anglers. Public access is available — the lake is on the Minnesota PCA public-access list. The lake has a long ice-out record — 32 observations on file, with a median ice-out around Apr 24. 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.