Ml-Seventeen Lake

Ml-Seventeen 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.

The lake sits in the mesotrophic zone — the band where most well-managed Minnesota lakes fall. Ml-Seventeen 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-Seventeen Lake is one of the larger lakes in Aitkin County, with 105.5 miles of shoreline supporting multiple distinct use patterns. Among the 53 graded lakes in Aitkin County, Ml-Seventeen Lake ranks 6 — in the top quartile locally.

Zebra mussels have been documented at Ml-Seventeen Lake, which alters the filter-feeding balance and can paradoxically increase water clarity while disrupting the food web. Muskie are on the species list at Ml-Seventeen Lake, alongside the lake's 21 other documented fish. Public access is available — the lake is on the Minnesota PCA public-access list. Ice-out has been logged at Ml-Seventeen 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.