Birch Lake vs Stony Lake
Water quality, depth, fish species, and recreation comparison.
Birch Lake and Stony Lake read the same on nutrients and algae. Both are in Cass County, Minnesota.
Birch Lake and Stony Lake are both in Minnesota — 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 readings are close: Birch Lake and Stony Lake sit within a narrow band of each other on phosphorus, chlorophyll-a and clarity. The per-parameter table below shows where the small differences actually live.
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
Good clarity, visible to about 14 ft.
Stony Lake
Crystal clear, you can see 23 ft down.
Side-by-Side Metrics
| Metric | Birch Lake | Stony Lake |
|---|---|---|
| Water Clarity | 14 ft | 23 ft Better |
| Phosphorus | 12 µg/L | 7 µg/L Better |
| Chlorophyll-a (Algae) | 4 µg/L | 2 µg/L Better |
| Maximum Depth | 45 ft | 50 ft Better |
| Surface Area | 1,267 acres | 563 acres |
| Public Access | Yes | Yes |
| Fish Species | 14 Better | 12 |
| Trophic State | mesotrophic | oligotrophic |
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 Stony Lake against a different lake.
Verdict
Both lakes earn the same Grade A. The tiebreakers come down to clarity (Birch Lake: 14 ft, Stony Lake: 23 ft) and what you want from the lake. Birch Lake supports more documented fish species.
Source: EPA National Aquatic Resource Surveys, 2026.