Little Iron Lake

Little Iron Lake carries a solid B grade — strong on most parameters, with measurements that hold up well across the summer season. 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 bottoms out at 18 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. Little Iron Lake covers 115 acres alongside 7.5 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within Cook County's 137 graded lakes, Little Iron Lake ranks 79 — below the local median, though not at the bottom.

Little Iron Lake has no invasive species recorded in Minnesota state databases as of 2025, though prevention practices still apply at all access points. Walleye are documented at Little Iron Lake, one of 7 fish species on record for the lake. Public access is available — the lake is on the Minnesota PCA public-access list. 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.