1
AFishtrap Lake
Vilas County, Wisconsin · mi from Boulder Lake
- +Two grade letters higher (C → A)
- ++6.6 ft water clarity
- +Lower phosphorus (10.7 vs 21.6 µg/L)
Cleaner Lakes Than Boulder Lake
5 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.
Boulder Lake carries a Grade C (Fair) water quality score. Within 30 miles, 5 lakes hold a higher grade. Fishtrap Lake (Vilas County, Grade A, null mi away) is the closest meaningful upgrade.
2
ALynx Lake
Vilas County, Wisconsin · mi from Boulder Lake
- +Two grade letters higher (C → A)
- ++7.2 ft water clarity
- +Lower phosphorus (9.5 vs 21.6 µg/L)
3
BLittle Crooked Lake
Vilas County, Wisconsin · mi from Boulder Lake
- +Higher grade (C → B)
- ++2.9 ft water clarity
4
BWildcat Lake
Vilas County, Wisconsin · mi from Boulder Lake
- +Higher grade (C → B)
- ++1.4 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.