Birch Lake vs Cass Lake Pike Bay
Water quality, depth, fish species, and recreation comparison.
Birch Lake and Cass Lake Pike Bay both received the same overall water quality grade of A (Excellent). 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 grade differences here are about the lakes themselves, not the agencies grading them. The grades are close: Birch Lake (A) and Cass Lake Pike Bay (A) 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.
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 |
|---|---|---|
| Overall Grade | A (Excellent) | A (Excellent) |
| Water Clarity | 14 ft | 13.6 ft |
| Phosphorus | 12 µg/L | 10.5 µg/L |
| Chlorophyll-a (Algae) | 4 µg/L | 3.4 µg/L |
| Maximum Depth | 45 ft | 95 ft |
| Surface Area | 1,267 acres | 4,756 acres |
| Public Access | Yes | Yes |
| Fish Species | 14 | 20 |
| Trophic State | mesotrophic | mesotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
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.