Cass Lake Allens Bay vs Drewery Lake
Water quality, depth, fish species, and recreation comparison.
Cass Lake Allens Bay has a higher water quality grade (A, Excellent) than Drewery Lake (C, Fair). Both are in Beltrami County, Minnesota.
Both Cass Lake Allens Bay and Drewery Lake 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 meaningfully apart: Cass Lake Allens Bay grades a A while Drewery Lake grades a C. That two-letter spread reflects real underlying differences — different watershed inputs, different depth profiles, or different monitoring rigor.
For a recreational visitor, the wider grade gap is decisive — Cass Lake Allens Bay is the better water-quality choice. For a researcher, the gap is the interesting part: what is different about the two watersheds, and which of those differences is mutable?
Cass Lake Allens Bay
Crystal clear, you can see 16.6 ft down.
Drewery Lake
Murky, only visible to about 3.5 ft.
Side-by-Side Metrics
| Metric | Cass Lake Allens Bay | Drewery Lake |
|---|---|---|
| Overall Grade | A (Excellent) | C (Fair) |
| Water Clarity | 16.6 ft | 3.5 ft |
| Phosphorus | 18.5 µg/L | 11.5 µg/L |
| Chlorophyll-a (Algae) | 4.7 µg/L | 2.7 µg/L |
| Maximum Depth | 120 ft | 120 ft |
| Surface Area | 15,958 acres | 15,958 acres |
| Public Access | Yes | Yes |
| Fish Species | 21 | 21 |
| Trophic State | mesotrophic | mesotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Cass Lake Allens Bay wins on overall water quality with a Grade A versus Drewery Lake's Grade C. Water clarity: 16.6 ft vs 3.5 ft. For fishing diversity, Cass Lake Allens Bay also leads with 21 species.
Source: EPA National Aquatic Resource Surveys, 2026.