Brown Lake

On the LakeGrade scale Brown Lake grades a B, with clarity at 8.5 ft and 17 µg/L of phosphorus placing it above the Minnesota median. Clarity is the limiting factor — phosphorus is reasonable but suspended particles or algal cells keep water transparency below Minnesota norms.

A TSI near 46 places Brown Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. The lake bottoms out at 27 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. The lake is compact at 72 acres, with 2.7 miles of shoreline and little volume to buffer nutrient inputs. Brown Lake ranks 57 of 187 in St. Louis County — solidly in the upper half of the local distribution.

Brown Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. 2 fish species are documented at Brown Lake, a mixed warm-water community typical for Minnesota lakes of this size. No formal public access is documented at Brown 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.