Birch Lake vs Cass Lake Pike Bay
Water quality, depth, fish species, and recreation comparison.
Birch Lake and Cass Lake Pike Bay read the same on nutrients and algae. Both are in Cass County, Minnesota.
Both Birch Lake and Cass Lake Pike Bay sit in Minnesota. A same-state comparison strips out the state-level water-quality regime as a variable: any differences in the readings here are about the lakes themselves, not the agencies sampling them. The readings are close: Birch Lake and Cass Lake Pike Bay 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.
Cass Lake Pike Bay
Good clarity, visible to about 13.6 ft.
Side-by-Side Metrics
| Metric | Birch Lake | Cass Lake Pike Bay |
|---|---|---|
| Water Clarity | 14 ft Better | 13.6 ft |
| Phosphorus | 12 µg/L | 10.5 µg/L Better |
| Chlorophyll-a (Algae) | 4 µg/L | 3.4 µg/L Better |
| Maximum Depth | 45 ft | 95 ft Better |
| Surface Area | 1,267 acres | 4,756 acres |
| Public Access | Yes | Yes |
| Fish Species | 14 | 20 Better |
| Trophic State | mesotrophic | mesotrophic |
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 Cass Lake Pike Bay against a different lake.
Verdict
Both lakes earn the same Grade A. The tiebreakers come down to clarity (Birch Lake: 14 ft, Cass Lake Pike Bay: 13.6 ft) and what you want from the lake. Birch Lake has fewer fish species than Cass Lake Pike Bay.
Source: EPA National Aquatic Resource Surveys, 2026.