Six Mile Lake vs Tamarack Bay Lake
Water quality, depth, fish species, and recreation comparison.
Six Mile Lake has a higher water quality grade (A, Excellent) than Tamarack Bay Lake (C, Fair). Both are in Cass County, Minnesota.
Six Mile Lake and Tamarack Bay Lake are both in Minnesota — a same-state head-to-head where the comparison comes down to lake-specific differences in depth, watershed, and monitoring history rather than the broader state-level water-quality regime. The grades are meaningfully apart: Six Mile Lake grades a A while Tamarack Bay 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 — Six Mile 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?
Six Mile Lake
Good clarity, visible to about 11.5 ft.
Tamarack Bay Lake
Good clarity, visible to about 11.5 ft.
Side-by-Side Metrics
| Metric | Six Mile Lake | Tamarack Bay Lake |
|---|---|---|
| Overall Grade | A (Excellent) | C (Fair) |
| Water Clarity | 11.5 ft | 11.5 ft |
| Phosphorus | 14.5 µg/L | 26 µg/L |
| Chlorophyll-a (Algae) | 6.7 µg/L | 4.6 µg/L |
| Maximum Depth | 68 ft | 69.8 ft |
| Surface Area | 1,323 acres | 56,471 acres |
| Public Access | Yes | Yes |
| Fish Species | 16 | 20 |
| Trophic State | mesotrophic | mesotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Six Mile Lake wins on overall water quality with a Grade A versus Tamarack Bay Lake's Grade C. Water clarity: 11.5 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.