Cleanest Lakes in Minnesota
Rainy Lake in Cass County leads the rankings with a water quality grade of A and 13.9 ft of clarity. Below are the top 50 cleanest monitored lakes in Minnesota, ranked by EPA water quality score.
Ranked List
| # | Lake | County | Grade | Clarity | Phosphorus | Algae |
|---|---|---|---|---|---|---|
| 1 | Rainy Lake | Cass | A | 13.9 ft | 11.5 µg/L | 1.8 µg/L |
| 2 | Crane Lake | Otter Tail | A | 9 ft | 15 µg/L | 6.4 µg/L |
| 3 | Lobster Lake | Douglas | A | 13 ft | 20.5 µg/L | 3.6 µg/L |
| 4 | East Fox Lake | Crow Wing | A | 16.4 ft | 10 µg/L | 2.7 µg/L |
| 5 | Deep Portage Lake | Cass | A | 15.4 ft | 9 µg/L | 1.6 µg/L |
| 6 | Clearwater Lake | Cook | A | 29 ft | 4 µg/L | 1.3 µg/L |
| 7 | Clearwater Lake | Wright | A | 9.8 ft | 22 µg/L | 6.3 µg/L |
| 8 | Clearwater Lake | Clearwater | A | 10 ft | 16 µg/L | 3.2 µg/L |
| 9 | Lower Hay Lake | Crow Wing | A | 18.5 ft | 13 µg/L | 2.7 µg/L |
| 10 | Latoka Lake | Douglas | A | 19 ft | 11 µg/L | 2.2 µg/L |
| 11 | Little Birch Lake | Todd | A | 13 ft | 19 µg/L | 3.1 µg/L |
| 12 | North Long Lake | Crow Wing | A | 15.1 ft | 14 µg/L | 2.7 µg/L |
| 13 | Bad Medicine Lake | Becker | A | 25 ft | 6 µg/L | 1.6 µg/L |
| 14 | Mud Lake | Becker | A | 12.5 ft | 22 µg/L | 5.9 µg/L |
| 15 | Big Lake | Beltrami | A | 9.7 ft | 15 µg/L | 4.8 µg/L |
| 16 | Big Lake | Carlton | A | 10 ft | 13.5 µg/L | 3.2 µg/L |
| 17 | Big Lake | Sherburne | A | 13.6 ft | 10.5 µg/L | 6.1 µg/L |
| 18 | Big Sugar Bush Lake | Becker | A | 16.5 ft | 10 µg/L | 2.7 µg/L |
| 19 | Pelican Lake | Otter Tail | A | 16.4 ft | 15 µg/L | 3 µg/L |
| 20 | Pelican Lake | Crow Wing | A | 14.3 ft | 11 µg/L | 2.7 µg/L |
| 21 | Fullers Lake | Beltrami | A | 15 ft | 10 µg/L | 2.4 µg/L |
| 22 | Birch Lake | Ramsey | A | 5.9 ft | 21 µg/L | 3.3 µg/L |
| 23 | Birch Lake | Wright | A | 15 ft | 17 µg/L | 4 µg/L |
| 24 | Birch Lake | Cass | A | 14 ft | 12 µg/L | 4 µg/L |
| 25 | Round Lake | Aitkin | A | 14.5 ft | 10 µg/L | 2.7 µg/L |
| 26 | Round Lake | Crow Wing | A | 13.5 ft | 17 µg/L | 2.7 µg/L |
| 27 | Round Lake | Beltrami | A | 18 ft | 7 µg/L | 1.9 µg/L |
| 28 | Round Lake | Otter Tail | A | 11.2 ft | 19 µg/L | 4.8 µg/L |
| 29 | Round Lake | Anoka | A | 8.9 ft | 19 µg/L | 5.3 µg/L |
| 30 | Ada Lake | Cass | A | 14 ft | 10 µg/L | 2.7 µg/L |
| 31 | Pike Lake | Cook | A | 17.4 ft | 7 µg/L | 2.6 µg/L |
| 32 | Whitefish Lake | Crow Wing | A | 14.4 ft | 14 µg/L | 2.7 µg/L |
| 33 | Horseshoe Lake | Crow Wing | A | 14.4 ft | 11 µg/L | 3.5 µg/L |
| 34 | Horseshoe Lake | Isanti | A | 3.5 ft | 13 µg/L | 2.7 µg/L |
| 35 | Farm Lake | Lake | A | 5.5 ft | 15 µg/L | 4.7 µg/L |
| 36 | Washburn Lake | Cass | A | 14.1 ft | 11 µg/L | 3.7 µg/L |
| 37 | Long Lake | Stearns | A | 13.5 ft | 19 µg/L | 4.4 µg/L |
| 38 | Long Lake | Kandiyohi | A | 10.5 ft | 13 µg/L | 4.5 µg/L |
| 39 | Long Lake | Clearwater | A | 20.5 ft | 7 µg/L | 1.4 µg/L |
| 40 | Long Lake | Cass | A | 21.5 ft | 9 µg/L | 3 µg/L |
| 41 | Long Lake | Beltrami | A | 20 ft | 7 µg/L | 1.8 µg/L |
| 42 | Long Lake | Otter Tail | A | 12.3 ft | 20 µg/L | 4.4 µg/L |
| 43 | Long Lake | Becker | A | 19.5 ft | 8 µg/L | 2.7 µg/L |
| 44 | Long Lake | Hubbard | A | 11.2 ft | 10 µg/L | 4.5 µg/L |
| 45 | Long Lake | Otter Tail | A | 12.1 ft | 19.5 µg/L | 5.3 µg/L |
| 46 | Long Lake | Beltrami | A | 10 ft | 17 µg/L | 4.9 µg/L |
| 47 | Long Lake | Otter Tail | A | 11.6 ft | 17 µg/L | 3.9 µg/L |
| 48 | Long Lake | Beltrami | A | 14 ft | 8 µg/L | 1.9 µg/L |
| 49 | Dead Lake | Otter Tail | A | 10.2 ft | 20 µg/L | 5.8 µg/L |
| 50 | Unnamed Lake | Crow Wing | A | 6.6 ft | 22 µg/L | 3.6 µg/L |
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