How Clean Is Gunflint Lake?
Gunflint Lake is among the cleanest lakes in Minnesota. It received a water quality grade of A (Excellent) based on EPA monitoring data. Water clarity (Secchi depth): 16.5 ft. Phosphorus: 5.5 µg/L. Chlorophyll-a (algae): 2.6 µg/L. Trophic State Index: 35.
Cleanliness Snapshot
| Metric | Gunflint Lake | Minnesota avg |
|---|---|---|
| Overall Grade | A | C |
| Water Clarity (Secchi) | 16.5 ft | — |
| Phosphorus | 5.5 µg/L | <30 = clean |
| Chlorophyll-a (Algae) | 2.6 µg/L | <10 = clean |
| Trophic State Index | 35 | <50 = clean |
How does Gunflint Lake compare?
Gunflint Lake's grade of A matches or beats the Minnesota state average of C. It ranks #20 of 44 lakes in Cook County by water quality score. Multi-year monitoring data shows water quality is declining based on 5 years of records.