Long Lake

Long 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 38 puts Long Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. At 61 ft of maximum depth, Long Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. The lake's 415 acres and 6.4 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Long Lake ranks 15 of 102 in Becker County, putting it in the upper tier of locally monitored lakes.

Zebra mussel presence at Long Lake means the lake's clarity numbers carry an asterisk — filtered water is not the same as nutrient-poor water. The fishery includes walleye alongside the lake's other 16 documented species — a notable draw for Minnesota anglers. A documented public access point at Long Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. Ice-out has been logged at Long Lake more than two dozen times, putting the median around Apr 19 — a useful baseline for tracking climate trends. 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.