1
CMark Twain Lake by Hwy J
Ralls County, Wisconsin · 0.1 mi from Mark Twain Lake
- +Higher grade (D → C)
- ++1.2 ft water clarity
- +Lower phosphorus (33.6 vs 60.8 µg/L)
Cleaner Lakes Than Mark Twain Lake
4 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.
Mark Twain Lake carries a Grade D (Poor) water quality score. Within 30 miles, 4 lakes hold a higher grade. Mark Twain Lake by Hwy J (Ralls County, Grade C, 0.1 mi away) is the closest meaningful upgrade.
2
CMark Twain Lake Indian Creek Arm
Ralls County, Wisconsin · 2.8 mi from Mark Twain Lake
- +Higher grade (D → C)
- ++1.3 ft water clarity
- +Lower phosphorus (31.5 vs 60.8 µg/L)
3
CMark Twain Lake
Monroe County, Wisconsin · 6.5 mi from Mark Twain Lake
- +Higher grade (D → C)
- ++1.3 ft water clarity
- +Lower phosphorus (36 vs 60.8 µg/L)
4
DHunnewell Lake
Shelby County, Wisconsin · 17.1 mi from Mark Twain Lake
- +Higher overall water quality score
- +Lower phosphorus (36 vs 60.8 µg/L)
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.