Is Boulder Lake Safe for Swimming?
Boulder Lake in Vilas County, Wisconsin has a water quality grade of C (Fair). Generally safe for swimming, moderate water quality. Water clarity: 5.6 ft visibility. Phosphorus: 21.6 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | C (Fair) |
| Water Clarity (Secchi Depth) | 5.6 ft |
| Phosphorus | 21.6 μg/L |
| Maximum Depth | 23 ft |
| Location | Vilas County, Wisconsin |
How does Boulder Lake compare?
With an overall water quality grade of C, Boulder Lake matches or beats the Wisconsin state average of Grade C. It ranks #137 of 191 lakes in Vilas County by water quality score.
Water clarity (Secchi depth) sits at 5.6 feet. That falls into moderate clarity — typical for lakes with some nutrient enrichment.