Ml-Thains Lake vs Outlet of Onamia Lake on the Rum River
Water quality, depth, fish species, and recreation comparison.
Outlet of Onamia Lake on the Rum River has a higher water quality grade (A, Excellent) than Ml-Thains Lake (B, Good). Both are in Mille Lacs County, Minnesota.
Ml-Thains Lake and Outlet of Onamia Lake on the Rum River 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. These two are within a letter of each other on the rubric — Ml-Thains Lake (B) versus Outlet of Onamia Lake on the Rum River (A). The deciding factors for a recreational visitor are likely physical (depth, access, fish species) rather than water-quality differences.
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.
Ml-Thains Lake
Murky, only visible to about 5.3 ft.
Outlet of Onamia Lake on the Rum River
No clarity data.
Side-by-Side Metrics
| Metric | Ml-Thains Lake | Outlet of Onamia Lake on the Rum River |
|---|---|---|
| Overall Grade | B (Good) | A (Excellent) |
| Water Clarity | 5.3 ft | No data |
| Phosphorus | 26 µg/L | 25 µg/L |
| Chlorophyll-a (Algae) | 3.5 µg/L | 0.6 µg/L |
| Maximum Depth | 42 ft | 10 ft |
| Surface Area | 128.3K acres | 1.0K acres |
| Public Access | Yes | No |
| Fish Species | 1 | 0 |
| Trophic State | mesotrophic | oligotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Outlet of Onamia Lake on the Rum River wins on overall water quality with a Grade A versus Ml-Thains Lake's Grade B. For more fish-species variety, Ml-Thains Lake edges ahead with 1 documented species.