Birch Lake vs Tamarack Bay Lake
Water quality, depth, fish species, and recreation comparison.
Birch Lake reads lower on nutrients and algae than Tamarack Bay Lake. Both are in Cass County, Minnesota.
Both Birch Lake and Tamarack Bay Lake 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 meaningfully apart: Birch Lake carries clearly lower phosphorus and chlorophyll-a readings than Tamarack Bay Lake. A spread that wide reflects real underlying differences, in watershed inputs, depth profiles, or monitoring rigor.
For a recreational visitor, the wider gap in the readings is decisive: Birch Lake has the lower nutrient and algae numbers. For a researcher, the gap is the interesting part: what is different about the two watersheds, and which of those differences is mutable?
Birch Lake
Good clarity, visible to about 14 ft.
Tamarack Bay Lake
Good clarity, visible to about 11.5 ft.
Side-by-Side Metrics
| Metric | Birch Lake | Tamarack Bay Lake |
|---|---|---|
| Water Clarity | 14 ft Better | 11.5 ft |
| Phosphorus | 12 µg/L Better | 26 µg/L |
| Chlorophyll-a (Algae) | 4 µg/L Better | 4.6 µg/L |
| Maximum Depth | 45 ft | 69.8 ft Better |
| Surface Area | 1,267 acres | 56,471 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.
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Compare Birch Lake or Tamarack Bay Lake against a different lake.
Verdict
Birch Lake reads lower on nutrients and algae than Tamarack Bay Lake. Water clarity: 14 ft vs 11.5 ft. For more fish-species variety, Tamarack Bay Lake edges ahead with 20 documented species.
Source: EPA National Aquatic Resource Surveys, 2026.