Birch Lake vs Boulder Lake
Water quality, depth, fish species, and recreation comparison.
Birch Lake and Boulder Lake read the same on nutrients and algae. Both are in Vilas County, Wisconsin.
Birch Lake and Boulder 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. These two sit close on the readings, Birch Lake versus Boulder Lake. The deciding factors for a recreational visitor are likely physical (depth, access, fish species) rather than water-quality differences.
With readings 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.
Birch Lake
Murky, only visible to about 6.5 ft.
Boulder Lake
Murky, only visible to about 5.6 ft.
Side-by-Side Metrics
| Metric | Birch Lake | Boulder Lake |
|---|---|---|
| Water Clarity | 6.5 ft Better | 5.6 ft |
| Phosphorus | 16.3 µg/L Better | 21.6 µg/L |
| Chlorophyll-a (Algae) | No data | No data |
| Maximum Depth | 45 ft Better | 23 ft |
| Surface Area | 506 acres | 516 acres |
| Public Access | Yes | Yes |
| Fish Species | 6 | 6 |
| Trophic State | mesotrophic | eutrophic |
A green ✓ marks the better value for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better). Surface area and trophic state carry no tick — a bigger lake is not a better lake.
Swap a lake
Compare Birch Lake or Boulder Lake against a different lake.
Verdict
Both lakes earn the same Grade B. The tiebreakers come down to clarity (Birch Lake: 6.5 ft, Boulder Lake: 5.6 ft) and what you want from the lake. Birch Lake matches its peer on species count.
Source: EPA National Aquatic Resource Surveys, 2026.