Fish Trap Lake vs Sullivan Lake
Water quality, depth, fish species, and recreation comparison.
Fish Trap Lake and Sullivan Lake read the same on nutrients and algae. Both are in Morrison County, Minnesota.
Fish Trap Lake and Sullivan 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 sit close on the readings, Fish Trap Lake versus Sullivan Lake. The deciding factors for a recreational visitor are likely physical (depth, access, fish species) rather than water-quality differences.
With readings 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.
Fish Trap Lake
Moderate clarity, visible to about 9.7 ft.
Sullivan Lake
Good clarity, visible to about 10.8 ft.
Side-by-Side Metrics
| Metric | Fish Trap Lake | Sullivan Lake |
|---|---|---|
| Water Clarity | 9.7 ft | 10.8 ft Better |
| Phosphorus | 22 µg/L | 14 µg/L Better |
| Chlorophyll-a (Algae) | 7 µg/L | 5 µg/L Better |
| Maximum Depth | 42 ft | 57 ft Better |
| Surface Area | 1,164 acres | 1,103 acres |
| Public Access | Yes | Yes |
| Fish Species | 18 | 18 |
| Trophic State | mesotrophic | mesotrophic |
A green ✓ marks the better value for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better). Surface area and trophic state carry no tick — a bigger lake is not a better lake.
Swap a lake
Compare Fish Trap Lake or Sullivan Lake against a different lake.
Verdict
Both lakes earn the same Grade A. The tiebreakers come down to clarity (Fish Trap Lake: 9.7 ft, Sullivan Lake: 10.8 ft) and what you want from the lake. Fish Trap Lake matches its peer on species count.
Source: EPA National Aquatic Resource Surveys, 2026.