Cass Lake vs Kitchi West Arm Lake
Water quality, depth, fish species, and recreation comparison.
Cass Lake has a higher water quality grade (A, Excellent) than Kitchi West Arm Lake (C, Fair). Both are in Beltrami County, Minnesota.
Both Cass Lake and Kitchi West Arm 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. Cass Lake (A) is materially cleaner than Kitchi West Arm Lake (C). A gap that wide is unlikely to close in a single year of remediation work; it reflects multi-decade differences in the lakes themselves.
For a recreational visitor, the wider grade gap is decisive — Cass Lake 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
Crystal clear, you can see 18.5 ft down.
Kitchi West Arm Lake
Good clarity, visible to about 10.2 ft.
Side-by-Side Metrics
| Metric | Cass Lake | Kitchi West Arm Lake |
|---|---|---|
| Overall Grade | A (Excellent) | C (Fair) |
| Water Clarity | 18.5 ft | 10.2 ft |
| Phosphorus | 11 µg/L | 22.5 µg/L |
| Chlorophyll-a (Algae) | 3.2 µg/L | 7.7 µg/L |
| Maximum Depth | 120 ft | 50 ft |
| Surface Area | 15,958 acres | 1,865 acres |
| Public Access | Yes | No |
| Fish Species | 21 | 16 |
| Trophic State | oligotrophic | mesotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Cass Lake wins on overall water quality with a Grade A versus Kitchi West Arm Lake's Grade C. Water clarity: 18.5 ft vs 10.2 ft. For fishing diversity, Cass Lake also leads with 21 species.
Source: EPA National Aquatic Resource Surveys, 2026.