Iron Lake
Iron Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 5 ft visibility. Maximum depth: 64 ft. Surface area: 1961.99 acres.
- Clarity
- 5 ft
- Max depth
- 64 ft
- Area
- 1,962 acres
- Public access
- No
Next lake in St. Louis County
Why Iron Lake has no grade
We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Iron Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Iron Lake is a 1,962-acre lake in St. Louis County, Minnesota with a maximum depth of 64 feet. The lake supports 9 documented fish species including black crappie, cisco species, and lake whitefish. No public access — the lake is private or restricted.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-07-06. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Iron Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Murky, only visible to about 5 ft. Trophic State Index: 54.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 5 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 54 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Iron Lake
Compare lakeside cabins, hotels, and vacation rentals near Iron Lake in St. Louis County, Minnesota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Iron Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 64 ft |
| Surface Area | 1,962 acres |
| Shoreline Length | 53.5 mi |
| Public Access | No |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Iron Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
EPA Impairment Status
Iron Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MN69-0121-00 · Official waterbody report
Nearby Lakes in St. Louis County
Frequently asked questions about Iron Lake
What is the water quality grade for Iron Lake?
- Iron Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 5 ft visibility. Maximum depth: 64 ft. Surface area: 1961.99 acres.
Is Iron Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Iron Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
How deep is Iron Lake?
- Iron Lake has a maximum depth of 64 feet. The lake covers 1961.99 acres.
What fish are in Iron Lake?
- Fish species found in Iron Lake include black crappie, cisco species, lake whitefish, northern pike, rock bass, sauger, walleye, white sucker, yellow perch. Iron Lake is located in St. Louis County, Minnesota.
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Where this data comes from
1 measurement from 1 monitoring station, 2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA1 sample · 2025
Analytical methods
- Field measurement/observation, generic method
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder