All Graded Lakes
Every monitored lake LakeQuality grades — 5,469 lakes across 12 states and 612 counties. Search for any lake by name, or browse by state, county, or grade.
Browse by Grade
Every lake earns an A–F report card from water clarity, phosphorus, and algae data.
Browse by State
All states →Water quality report cards for every state we cover, sorted by number of graded lakes.
Minnesota
2,403 lakes75 counties graded
Wisconsin
1,422 lakes69 counties graded
Michigan
628 lakes61 counties graded
Missouri
317 lakes78 counties graded
New York
189 lakes47 counties graded
Iowa
170 lakes75 counties graded
North Dakota
150 lakes48 counties graded
Illinois
144 lakes45 counties graded
Indiana
22 lakes7 counties graded
Ohio
17 lakes9 counties graded
South Dakota
4 lakes3 counties graded
Pennsylvania
3 lakes3 counties graded
Browse by County
All 612 counties ranked by average lake water quality — find the cleanest lake counties for a cabin, a fishing trip, or a move.
View county rankings →Cleanest Lakes Right Now
The top-graded lakes across all 12 states. See the full ranking →
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