Blackduck Lake vs Gull Lake
Water quality, depth, fish species, and recreation comparison.
Gull Lake has a higher water quality grade (C, Fair) than Blackduck Lake (C, Fair). Both are in Beltrami County, Minnesota.
Blackduck Lake and Gull Lake are both in Minnesota — a same-state head-to-head where the comparison comes down to lake-specific differences in depth, watershed, and monitoring history rather than the broader state-level water-quality regime. These two are within a letter of each other on the rubric — Blackduck Lake (C) versus Gull 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.
Blackduck Lake
Murky, only visible to about 6.2 ft.
Gull Lake
Murky, only visible to about 5.9 ft.
Side-by-Side Metrics
| Metric | Blackduck Lake | Gull Lake |
|---|---|---|
| Overall Grade | C (Fair) | C (Fair) |
| Water Clarity | 6.2 ft | 5.9 ft |
| Phosphorus | 39.5 µg/L | 27 µg/L |
| Chlorophyll-a (Algae) | No data | No data |
| Maximum Depth | 28 ft | 23 ft |
| Surface Area | 2.7K acres | 2.3K acres |
| Public Access | Yes | Yes |
| Fish Species | 1 | 1 |
| Trophic State | eutrophic | eutrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Gull Lake wins on overall water quality with a Grade C versus Blackduck Lake's Grade C. Water clarity: 5.9 ft vs 6.2 ft. For fishing diversity, Gull Lake also leads with 1 species.