Lake Winnibigoshish vs Portage Lake
Water quality, depth, fish species, and recreation comparison.
Lake Winnibigoshish and Portage Lake both received the same overall water quality grade of C (Fair). Both are in Cass County, Minnesota.
Both Lake Winnibigoshish and Portage 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. These two are within a letter of each other on the rubric — Lake Winnibigoshish (C) versus Portage Lake (C). 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.
Lake Winnibigoshish
Good clarity, visible to about 12.1 ft.
Portage Lake
Moderate clarity, visible to about 7.5 ft.
Side-by-Side Metrics
| Metric | Lake Winnibigoshish | Portage Lake |
|---|---|---|
| Overall Grade | C (Fair) | C (Fair) |
| Water Clarity | 12.1 ft | 7.5 ft |
| Phosphorus | 29 µg/L | 22 µg/L |
| Chlorophyll-a (Algae) | 5.2 µg/L | 7.1 µg/L |
| Maximum Depth | 69.8 ft | 55 ft |
| Surface Area | 56,471 acres | 1,539 acres |
| Public Access | Yes | Yes |
| Fish Species | 20 | 15 |
| Trophic State | mesotrophic | mesotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Both lakes earn the same Grade C. The tiebreakers come down to clarity (Lake Winnibigoshish: 12.1 ft, Portage Lake: 7.5 ft) and what you want from the lake. Lake Winnibigoshish supports more documented fish species.
Source: EPA National Aquatic Resource Surveys, 2026.