Boulder Lake vs Kentuck Lake
Water quality, depth, fish species, and recreation comparison.
Boulder Lake and Kentuck Lake both received the same overall water quality grade of B (Good). Both are in Vilas County, Wisconsin.
Boulder Lake and Kentuck Lake are both in Wisconsin — a same-state head-to-head where the comparison comes down to lake-specific differences in depth, watershed, and monitoring history rather than the broader state-level water-quality regime. The grades are close: Boulder Lake (B) and Kentuck Lake (B) are within one letter of each other on the LakeGrade rubric. The per-parameter sub-grades below will show where the small differences actually live.
With grades this close, the choice between the two lakes turns on non-water-quality factors: depth, fish species, public access, distance from home. The per-lake pages below cover all of those.
Boulder Lake
Murky, only visible to about 5.6 ft.
Kentuck Lake
Moderate clarity, visible to about 9.5 ft.
Side-by-Side Metrics
| Metric | Boulder Lake | Kentuck Lake |
|---|---|---|
| Overall Grade | B (Good) | B (Good) |
| Water Clarity | 5.6 ft | 9.5 ft |
| Phosphorus | 21.6 µg/L | 24.3 µg/L |
| Chlorophyll-a (Algae) | No data | No data |
| Maximum Depth | 23 ft | 40 ft |
| Surface Area | 516 acres | 1,001 acres |
| Public Access | Yes | Yes |
| Fish Species | 6 | 5 |
| Trophic State | eutrophic | mesotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Both lakes earn the same Grade B. The tiebreakers come down to clarity (Boulder Lake: 5.6 ft, Kentuck Lake: 9.5 ft) and what you want from the lake. Boulder Lake supports more documented fish species.
Source: EPA National Aquatic Resource Surveys, 2026.