Is Mason Lake Safe for Swimming?
Mason Lake in Otter Tail County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Not rated for swimming — there is not enough monitoring data to judge this lake. Water clarity: 3 ft visibility. Phosphorus: 21 µg/L. Chlorophyll-a (algae): 16.9 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | NR (Not rated) |
| Water Clarity (Secchi Depth) | 3 ft |
| Phosphorus | 21 μg/L |
| Chlorophyll-a (Algae) | 16.9 μg/L |
| Maximum Depth | 108 ft |
| Location | Otter Tail County, Minnesota |
How does Mason Lake compare?
Mason Lake is not rated for water quality — its monitoring record does not meet the evidence bar, so it is not compared with the Minnesota state average.
Water clarity (Secchi depth) sits at 3 feet. That falls into moderate clarity — typical for lakes with some nutrient enrichment. Algae levels (chlorophyll-a) measure 16.9 µg/L — moderate; acceptable for swimming on most days, but worth checking advisories.