Lower Sucker Lake vs Portage Lake
Water quality, depth, fish species, and recreation comparison.
Lower Sucker Lake has a higher water quality grade (A, Excellent) than Portage Lake (C, Fair). Both are in Cass County, Minnesota.
Both Lower Sucker Lake 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. Lower Sucker Lake (A) is materially cleaner than Portage 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 — Lower Sucker 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?
Lower Sucker Lake
Moderate clarity, visible to about 8.3 ft.
Portage Lake
Moderate clarity, visible to about 7.5 ft.
Side-by-Side Metrics
| Metric | Lower Sucker Lake | Portage Lake |
|---|---|---|
| Overall Grade | A (Excellent) | C (Fair) |
| Water Clarity | 8.3 ft | 7.5 ft |
| Phosphorus | 21 µg/L | 22 µg/L |
| Chlorophyll-a (Algae) | 6.5 µg/L | 7.1 µg/L |
| Maximum Depth | 35 ft | 55 ft |
| Surface Area | 592 acres | 1,539 acres |
| Public Access | Yes | Yes |
| Fish Species | 14 | 15 |
| Trophic State | mesotrophic | mesotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Lower Sucker Lake wins on overall water quality with a Grade A versus Portage Lake's Grade C. Water clarity: 8.3 ft vs 7.5 ft. For more fish-species variety, Portage Lake edges ahead with 15 documented species.
Source: EPA National Aquatic Resource Surveys, 2026.