O'Leary Lake

O'Leary Lake comes in at a B on the grading rubric — a respectable showing for a Minnesota lake of its size and depth.

A TSI near 43 places O'Leary Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. At 52 ft of maximum depth, O'Leary Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. At 202 acres, O'Leary Lake fits the Minnesota median for monitored lakes, with 2.5 miles of shoreline. O'Leary Lake ranks 44 of 187 in St. Louis County, putting it in the upper tier of locally monitored lakes.

O'Leary 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 O'Leary Lake, one of 9 fish species on record for the lake. No formal public access is documented at O'Leary Lake — most use is by shoreline residents and their guests. 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.