Lakes That Made the Biggest Comeback
Reviewed by LakeQuality Editorial Team · Updated
1,768 lakes across the 12 states we track show improving water quality trends based on multi-year monitoring data. But the most impressive are the lakes that now earn A or B grades while still showing upward trajectories, evidence of sustained, meaningful recovery.
These 25 lakes represent the best-case scenario: excellent current water quality that continues to get better.
| Lake | County | State | Grade | Clarity | Years Data |
|---|---|---|---|---|---|
| Big Sugar Bush Lake | Becker | MN | A | 16.5 ft | 6 |
| Round Lake | Cook | MN | A | 16.5 ft | 6 |
| Round Lake | Beltrami | MN | A | 18 ft | 6 |
| Horseshoe Lake | Cass | MN | A | 21 ft | 6 |
| Long Lake | Becker | MN | A | 19.3 ft | 6 |
| West Twin Lake | Crow Wing | MN | A | 20 ft | 6 |
| Star Lake | Crow Wing | MN | A | 19 ft | 6 |
| Star Lake | Otter Tail | MN | A | 17 ft | 6 |
| Fish Lake | Otter Tail | MN | A | 18 ft | 6 |
| Birch Lake | Wright | MN | A | 15 ft | 6 |
| Girl Lake | Cass | MN | A | 17.6 ft | 6 |
| Big Pine Lake | Aitkin | MN | A | 17 ft | 6 |
| Alexander Lake | Morrison | MN | A | 16.5 ft | 6 |
| Deep Portage Lake | Cass | MN | A | 15.4 ft | 6 |
| Lower Hay Lake | Crow Wing | MN | A | 18.5 ft | 6 |
| Maple Lake | Itasca | MN | A | 15.3 ft | 4 |
| Trout Lake | Itasca | MN | A | 16 ft | 6 |
| Trout Lake | Itasca | MN | A | 18 ft | 5 |
| Bear Lake | Lake | MN | A | 17.4 ft | 2 |
| Andrusia Lake | Beltrami | MN | A | 15.1 ft | 6 |
| Green Lake | Beltrami | MN | A | 18.5 ft | 6 |
| Island Lake | Cass | MN | A | 15.5 ft | 6 |
| Island Lake | Becker | MN | A | 15 ft | 6 |
| Island Lake | Beltrami | MN | A | 16 ft | 6 |
| Island Lake | Hubbard | MN | A | 16.4 ft | 6 |
Why Do Lakes Improve?
Lake water quality improves when nutrient inputs decrease. Common causes include:
- Agricultural best management practices reducing phosphorus runoff
- Upgraded wastewater treatment facilities upstream
- Shoreline buffer restoration preventing erosion
- Invasive species management (e.g., carp removal restoring clarity)
- Reduced impervious surface runoff from stormwater improvements
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