Ossawinnamakee Lake vs Sibley Lake
Water quality, depth, fish species, and recreation comparison.
Ossawinnamakee Lake has a higher water quality grade (A, Excellent) than Sibley Lake (C, Fair). Both are in Crow Wing County, Minnesota.
Ossawinnamakee Lake and Sibley 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. Ossawinnamakee Lake (A) is materially cleaner than Sibley 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 — Ossawinnamakee 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?
Ossawinnamakee Lake
Crystal clear, you can see 20 ft down.
Sibley Lake
Murky, only visible to about 4.9 ft.
Side-by-Side Metrics
| Metric | Ossawinnamakee Lake | Sibley Lake |
|---|---|---|
| Overall Grade | A (Excellent) | C (Fair) |
| Water Clarity | 20 ft | 4.9 ft |
| Phosphorus | 10 µg/L | 26 µg/L |
| Chlorophyll-a (Algae) | No data | No data |
| Maximum Depth | - | - |
| Surface Area | 662 acres | 418 acres |
| Public Access | Unknown | Unknown |
| Fish Species | 1 | 1 |
| Trophic State | oligotrophic | eutrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Ossawinnamakee Lake wins on overall water quality with a Grade A versus Sibley Lake's Grade C. Water clarity: 20 ft vs 4.9 ft. For fishing diversity, Ossawinnamakee Lake also leads with 1 species.