Ban Lake

On the scoring rubric Ban Lake grades a D: clarity at 6.0 ft and phosphorus readings still being added keep it in the lower bracket for St. Louis County. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. Ban Lake is a shallow lake at 10 ft maximum depth, which means it warms quickly, mixes constantly, and amplifies nutrient inputs. Ban Lake covers 389 acres alongside 7.3 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within the 187 graded lakes of St. Louis County, Ban Lake sits at rank 176, near the bottom of the county list.

Ban Lake has no invasive species recorded in Minnesota state databases as of 2023, though prevention practices still apply at all access points. The fishery includes walleye alongside the lake's other 9 documented species — a notable draw for Minnesota anglers. Public access is available — the lake is on the Minnesota PCA public-access list. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.