Lake Winnibigoshish vs Six Mile Lake
Water quality, depth, fish species, and recreation comparison.
Six Mile Lake has a higher water quality grade (A, Excellent) than Lake Winnibigoshish (C, Fair). Both are in Cass County, Minnesota.
Both Lake Winnibigoshish and Six Mile 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. Six Mile Lake (A) is materially cleaner than Lake Winnibigoshish (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 — 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?
Lake Winnibigoshish
Good clarity, visible to about 12.1 ft.
Six Mile Lake
Good clarity, visible to about 11.5 ft.
Side-by-Side Metrics
| Metric | Lake Winnibigoshish | Six Mile Lake |
|---|---|---|
| Overall Grade | C (Fair) | A (Excellent) |
| Water Clarity | 12.1 ft | 11.5 ft |
| Phosphorus | 29 µg/L | 14.5 µg/L |
| Chlorophyll-a (Algae) | 5.2 µg/L | 6.7 µg/L |
| Maximum Depth | 69.8 ft | 68 ft |
| Surface Area | 56,471 acres | 1,323 acres |
| Public Access | Yes | Yes |
| Fish Species | 20 | 16 |
| 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 Lake Winnibigoshish's Grade C. Water clarity: 11.5 ft vs 12.1 ft. For more fish-species variety, Lake Winnibigoshish edges ahead with 20 documented species.
Source: EPA National Aquatic Resource Surveys, 2026.