Blue Lake

Blue 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.

A TSI value of 34 puts Blue Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. The lake's 84 ft maximum depth is in the upper tier for Minnesota — deep enough for cold-water fish to find refuge in summer. Blue Lake covers 336 acres alongside 3.2 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Among the 77 graded lakes in Hubbard County, Blue Lake ranks 2 — in the top quartile locally.

No invasive species are currently listed at Blue Lake — the lake remains off the Minnesota infested-waters roster. Walleye are documented at Blue Lake, one of 13 fish species on record for the lake. A documented public access point at Blue Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The lake has a partial ice record — 20 observed ice-outs, centered near Apr 26. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.