Frost Lake

Frost Lake comes in at a B on the grading rubric — a respectable showing for a Minnesota lake of its size and depth. 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 near 43 places Frost Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. At 88 ft of maximum depth, Frost Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. The lake's 284 acres and 4.2 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Frost Lake ranks 68 of 137 in Cook County — solidly in the upper half of the local distribution.

No invasive species are currently listed at Frost Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Frost Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. The lake lacks a documented public access point, so visitor use is limited. 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.