Bear Island Lake

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

A TSI near 49 places Bear Island Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. At 62 ft of maximum depth, Bear Island Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. With 2,362 acres of surface and 28.5 miles of shoreline, Bear Island Lake is a large water by Minnesota standards — recreational pressure is spread across a long shoreline. Bear Island Lake sits at rank 108 of 187 in St. Louis County, in the lower half of the local distribution.

Bear Island Lake has no invasive species recorded in Minnesota state databases as of 2023, though prevention practices still apply at all access points. Walleye are documented at Bear Island Lake, one of 13 fish species on record for the lake. Public access is available — the lake is on the Minnesota PCA public-access list. The lake has a partial ice record — 6 observed ice-outs, centered near Apr 28. 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.