Is Upper Cullen Lake Safe for Swimming?
Upper Cullen Lake in Crow Wing County, Minnesota has a water quality grade of A (Excellent). Excellent for swimming, crystal clear water with minimal algae. Water clarity: 8.7 ft visibility. Phosphorus: 23 µg/L. Chlorophyll-a (algae): 6.8 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | A (Excellent) |
| Water Clarity (Secchi Depth) | 8.7 ft |
| Phosphorus | 23 μg/L |
| Chlorophyll-a (Algae) | 6.8 μg/L |
| Maximum Depth | 40 ft |
| Location | Crow Wing County, Minnesota |
How does Upper Cullen Lake compare?
With an overall water quality grade of A, Upper Cullen Lake matches or beats the Minnesota state average of Grade C. It ranks #56 of 85 lakes in Crow Wing County by water quality score.
Water clarity (Secchi depth) sits at 8.7 feet. That puts the lake in good clarity range, with limited algae interference. Algae levels (chlorophyll-a) measure 6.8 µg/L — low and well within safe swimming guidelines.