South Lake

South Lake sits at a C on the grading scale — not impaired, not pristine, with summer measurements that vary year to year.

A TSI near 47 places South Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. At 140 ft of maximum depth, South Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. With 1,145 acres of surface and 15.0 miles of shoreline, South Lake is a large water by Minnesota standards — recreational pressure is spread across a long shoreline. Within Cook County's 128 graded lakes, South Lake ranks 87 — below the local median, though not at the bottom.

No invasive species are currently listed at South Lake — the lake remains off the Minnesota infested-waters roster. Bass fishing is part of the appeal: the species list runs to 6, anchored by largemouth and/or smallmouth bass. 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.