Ml-Peterson Lake

Ml-Peterson 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 sits in the mesotrophic zone — the band where most well-managed Minnesota lakes fall. Ml-Peterson Lake reaches 42 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. At 128,250 acres, Ml-Peterson Lake is one of the larger lakes in Mille Lacs County, with 105.5 miles of shoreline supporting multiple distinct use patterns. Ml-Peterson Lake ranks 5 of 11 in Mille Lacs County — solidly in the upper half of the local distribution.

Zebra mussel presence at Ml-Peterson Lake means the lake's clarity numbers carry an asterisk — filtered water is not the same as nutrient-poor water. Muskie are on the species list at Ml-Peterson Lake, alongside the lake's 21 other documented fish. A documented public access point at Ml-Peterson Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. Ice-out has been logged at Ml-Peterson Lake more than two dozen times, putting the median around Apr 25 — a useful baseline for tracking climate trends. Multiple sampling years from Minnesota PCA volunteers and partner agencies back the grade, so the letter should hold steady absent a major watershed shift.