Birch Lake

Birch 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.

Trophically, Birch Lake reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. The lake bottoms out at 45 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. Birch Lake covers 1,267 acres alongside 15.3 miles of shoreline, large enough that conditions can vary meaningfully between bays. Birch Lake ranks 51 of 133 in Cass County — solidly in the upper half of the local distribution.

No invasive species are currently listed at Birch Lake — the lake remains off the Minnesota infested-waters roster. The fishery includes walleye alongside the lake's other 14 documented species — a notable draw for Minnesota anglers. A documented public access point at Birch Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. Ice-out has been recorded 6 times at Birch Lake, with a median around Apr 17. 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.