Pine Lake

Pine Lake sits at the top of the Minnesota PCA grading rubric with an A, a mark reached by the cleanest lakes in Minnesota. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

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. Pine Lake is unusually deep for Minnesota at 59 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. At 178 acres, Pine Lake fits the Minnesota median for monitored lakes, with 3.3 miles of shoreline. Among the 16 graded lakes in Morrison County, Pine Lake ranks 3 — in the top quartile locally.

No invasive species are currently listed at Pine Lake — the lake remains off the Minnesota infested-waters roster. Walleye are documented at Pine Lake, one of 12 fish species on record for the lake. Public access is available — the lake is on the Minnesota PCA public-access list. The lake has a partial ice record — 10 observed ice-outs, centered near Apr 13. 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.