Portage Lake vs Six Mile Lake
Water quality, depth, fish species, and recreation comparison.
Six Mile Lake has a higher water quality grade (B, Good) than Portage Lake (B, Good). Both are in Cass County, Minnesota.
Both Portage Lake 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. The grades are close: Portage Lake (B) and Six Mile Lake (B) are within one letter of each other on the LakeGrade rubric. The per-parameter sub-grades below will show where the small differences actually live.
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.
Portage Lake
Moderate clarity, visible to about 7.5 ft.
Six Mile Lake
Good clarity, visible to about 11.5 ft.
Side-by-Side Metrics
| Metric | Portage Lake | Six Mile Lake |
|---|---|---|
| Overall Grade | B (Good) | B (Good) |
| Water Clarity | 7.5 ft | 11.5 ft |
| Phosphorus | 23 µg/L | 16 µg/L |
| Chlorophyll-a (Algae) | 6.1 µg/L | 6.7 µg/L |
| Maximum Depth | 55 ft | 68 ft |
| Surface Area | 1.5K acres | 1.3K acres |
| Public Access | Yes | Yes |
| Fish Species | 1 | 1 |
| 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 B versus Portage Lake's Grade B. Water clarity: 11.5 ft vs 7.5 ft. For fishing diversity, Six Mile Lake also leads with 1 species.