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LakeQuality
C

Bog Lake

St. Louis County, MinnesotaEutrophic

Bog Lake sits at a C on the grading scale — not impaired, not pristine, with summer measurements that vary year to year. The lake's weakest score is on Secchi depth — the water looks more turbid than its phosphorus number alone would predict.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake's surface area is not consistently recorded across state datasets — physical context remains partial. Bog Lake sits at rank 125 of 187 in St. Louis County, in the lower half of the local distribution.

No invasive species are currently listed at Bog Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Bog Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. 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.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2022-09-29. Grade methodology: LakeGrade methodology.

Swimming Safety

Generally safe for swimming, moderate water quality

Water Quality Grade: C, Fair

Very murky, less than 3.3 ft of visibility. Phosphorus level: 14 µg/L. Trophic State Index: 51.

MetricValueGrade
Water Clarity (Secchi Depth)3.3 ftF
Phosphorus14 µg/LA
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)51Eutrophic

High nutrients, frequent algae, reduced clarity

Location

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County Ranking

Ranked #125 of 187 lakes in St. Louis County

Nearby Lakes in St. Louis County

Eutrophic Lakes in Minnesota

Data Sources

Water quality data from the EPA Water Quality Portal

Grading methodology based on Metropolitan Council standards

Most recent sample: 2022-09-29

Monitoring stations: 1