How Clean Is Upper Gull Lake?
Upper Gull 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): 10 ft. Phosphorus: 19 µg/L. Trophic State Index: 45.
Cleanliness Snapshot
| Metric | Upper Gull Lake | Minnesota avg |
|---|---|---|
| Overall Grade | A | C |
| Water Clarity (Secchi) | 10 ft | — |
| Phosphorus | 19 µg/L | <30 = clean |
| Trophic State Index | 45 | <50 = clean |
How does Upper Gull Lake compare?
Upper Gull Lake's grade of A matches or beats the Minnesota state average of C. It ranks #56 of 133 lakes in Cass County by water quality score. Multi-year monitoring data shows water quality is declining based on 5 years of records.