1
ACrooked Lake
Crow Wing County, Minnesota · 7.8 mi from Upper South Long Lake
- +Higher grade (B → A)
- ++9 ft water clarity
- +Lower phosphorus (10 vs 17 µg/L)
Cleaner Lakes Than Upper South Long Lake
4 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.
Upper South Long Lake carries a Grade B (Good) water quality score. Within 30 miles, 4 lakes hold a higher grade. Crooked Lake (Crow Wing County, Grade A, 7.8 mi away) is the closest meaningful upgrade.
2
APortage Lake
Crow Wing County, Minnesota · 6.3 mi from Upper South Long Lake
- +Higher grade (B → A)
- ++5.5 ft water clarity
3
AHanks Lake
Crow Wing County, Minnesota · 7.2 mi from Upper South Long Lake
- +Higher grade (B → A)
- ++6.5 ft water clarity
4
AClearwater Lake
Crow Wing County, Minnesota · 8.1 mi from Upper South Long Lake
- +Higher grade (B → A)
- ++7.1 ft water clarity
How this list is built
Every lake on LakeQuality has a calculated grade from EPA Water Quality Portal samples — secchi depth, total phosphorus, and chlorophyll-a measured against Metropolitan Council thresholds. To suggest cleaner alternatives, we filter lakes within 30 miles to those with a strictly higher numeric score, then rank by grade improvement with a small proximity tiebreak. Cross-state and limited-data lakes are excluded so the list stays locally relevant.