Blackwater Lake vs Mule Lake
Water quality, depth, fish species, and recreation comparison.
Mule Lake has a higher water quality grade (A, Excellent) than Blackwater Lake (B, Good). Both are in Cass County, Minnesota.
Both Blackwater Lake and Mule 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 — Blackwater Lake (B) versus Mule Lake (A). 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.
Blackwater Lake
Good clarity, visible to about 13.1 ft.
Mule Lake
Crystal clear, you can see 18.7 ft down.
Side-by-Side Metrics
| Metric | Blackwater Lake | Mule Lake |
|---|---|---|
| Overall Grade | B (Good) | A (Excellent) |
| Water Clarity | 13.1 ft | 18.7 ft |
| Phosphorus | No data | 9 µg/L |
| Chlorophyll-a (Algae) | No data | No data |
| Maximum Depth | 67 ft | 47 ft |
| Surface Area | 771.45 acres | 524.58 acres |
| Public Access | Yes | Yes |
| Fish Species | 1 | 1 |
| Trophic State | mesotrophic | oligotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Mule Lake wins on overall water quality with a Grade A versus Blackwater Lake's Grade B. Water clarity: 18.7 ft vs 13.1 ft. For fishing diversity, Mule Lake also leads with 1 species.