Canyon Lake vs Mirror Lake
Water quality, depth, fish species, and recreation comparison.
Canyon Lake has a higher water quality grade (A, Excellent) than Mirror Lake (F, Very Poor).
Canyon Lake is in South Dakota; Mirror Lake is in North Dakota. Cross-state comparisons carry an extra wrinkle — Minnesota PCA and Wisconsin DNR use slightly different sampling cadences and station coverage, though both feed the same EPA Water Quality Portal. Canyon Lake (A) is materially cleaner than Mirror Lake (F). 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 — Canyon 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?
Canyon Lake
No clarity data.
Mirror Lake
Very murky, less than 2.1 ft of visibility.
Side-by-Side Metrics
| Metric | Canyon Lake | Mirror Lake |
|---|---|---|
| Overall Grade | A (Excellent) | F (Very Poor) |
| Water Clarity | No data | 2.1 ft |
| Phosphorus | No data | No data |
| Chlorophyll-a (Algae) | 1.3 µg/L | 31.6 µg/L |
| Maximum Depth | - | - |
| Surface Area | 29 acres | 94.33 acres |
| Public Access | Unknown | Unknown |
| Fish Species | 0 | 0 |
| Trophic State | oligotrophic | eutrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Canyon Lake wins on overall water quality with a Grade A versus Mirror Lake's Grade F. For fishing diversity, Canyon Lake also leads with 0 species.