Cleanest Lakes in Cass County, Minnesota
Long Lake in Cass County leads the rankings with a water quality grade of A and 21.5 ft of clarity. Below are the top 50 cleanest monitored lakes in Cass County, Minnesota, ranked by EPA water quality score.
Ranked List
| # | Lake | County | Grade | Clarity | Phosphorus | Algae |
|---|---|---|---|---|---|---|
| 1 | Long Lake | Cass | A | 21.5 ft | 9 µg/L | - |
| 2 | Woman Lake | Cass | A | 15 ft | 11 µg/L | - |
| 3 | Girl Lake | Cass | A | 17.6 ft | 12 µg/L | - |
| 4 | Gull Lake | Cass | A | 15 ft | 14 µg/L | - |
| 5 | Deep Portage Lake | Cass | A | 15.4 ft | 9 µg/L | - |
| 6 | Island Lake | Cass | A | 15.5 ft | 12 µg/L | - |
| 7 | Island Lake | Cass | A | 17.5 ft | 9 µg/L | - |
| 8 | Crystal Lake | Cass | A | 16 ft | 7 µg/L | - |
| 9 | Pleasant Lake | Cass | A | 15.5 ft | 10 µg/L | - |
| 10 | Webb Lake | Cass | A | 18 ft | 9.5 µg/L | - |
| 11 | Howard Lake | Cass | A | 16 ft | 9.5 µg/L | - |
| 12 | Pine Lake | Cass | A | 16 ft | 13 µg/L | 3.2 µg/L |
| 13 | Thunder Lake | Cass | A | 16.5 ft | 10 µg/L | - |
| 14 | Little Portage Lake | Cass | A | 16.4 ft | 12 µg/L | - |
| 15 | Ponto Lake | Cass | A | 19 ft | 8 µg/L | - |
| 16 | Ten Mile Lake | Cass | A | 20.5 ft | 9 µg/L | - |
| 17 | Sylvan Lake | Cass | A | 19.5 ft | 7 µg/L | - |
| 18 | Hunter Lake | Cass | A | 31 ft | 11 µg/L | - |
| 19 | Stony Lake | Cass | A | 23 ft | 7 µg/L | - |
| 20 | Barnum Lake | Cass | A | 16.1 ft | 9 µg/L | - |
| 21 | Mule Lake | Cass | A | 18 ft | 10 µg/L | - |
| 22 | Pillager Lake | Cass | A | 15.1 ft | 7 µg/L | - |
| 23 | Cooper Lake | Cass | A | 17.1 ft | 13 µg/L | - |
| 24 | Mckeown Lake | Cass | A | 16.1 ft | 11 µg/L | - |
| 25 | Kid Lake | Cass | A | 15.5 ft | 11.5 µg/L | - |
| 26 | Walker Bay Lake | Cass | A | 16.5 ft | - | 2.3 µg/L |
| 27 | Agency Bay Lake | Cass | A | 15.2 ft | - | 2.7 µg/L |
| 28 | Kabekona Bay Lake | Cass | A | 17.2 ft | - | 2.7 µg/L |
| 29 | Jack Lake | Cass | A | 15.7 ft | 7 µg/L | 3.1 µg/L |
| 30 | Big Deep Lake | Cass | A | 19.4 ft | 7 µg/L | - |
| 31 | Crooked Lake | Cass | A | 12 ft | 12 µg/L | 4.3 µg/L |
| 32 | Steamboat Lake | Cass | A | 12 ft | 11 µg/L | 3.7 µg/L |
| 33 | Boxell Lake | Cass | A | 14.5 ft | 14 µg/L | 3.8 µg/L |
| 34 | Ada Lake | Cass | A | 14 ft | 10 µg/L | - |
| 35 | Birch Lake | Cass | A | 14 ft | 12 µg/L | - |
| 36 | Upper Trelipe Lake | Cass | A | 14 ft | 12 µg/L | - |
| 37 | Washburn Lake | Cass | A | 14.1 ft | 11 µg/L | - |
| 38 | Maple Lake | Cass | A | 13.3 ft | - | 2.7 µg/L |
| 39 | Rainy Lake | Cass | A | 13.9 ft | 11.5 µg/L | - |
| 40 | Spider Lake | Cass | A | 10.2 ft | 12.5 µg/L | - |
| 41 | Ray Lake | Cass | A | 10.3 ft | 11 µg/L | - |
| 42 | Child Lake | Cass | A | 12.1 ft | 14 µg/L | - |
| 43 | Baby Lake | Cass | A | 12.5 ft | 10 µg/L | - |
| 44 | Inguadona Lake | Cass | A | 12 ft | 15 µg/L | - |
| 45 | Roosevelt Lake | Cass | A | 11.1 ft | 12.5 µg/L | - |
| 46 | Broadwater Bay Lake | Cass | A | 14.4 ft | 13.5 µg/L | - |
| 47 | Man Lake | Cass | A | 11 ft | 10 µg/L | - |
| 48 | Blackwater Lake | Cass | A | 14.1 ft | 12 µg/L | - |
| 49 | Little Boy Lake | Cass | A | 11 ft | 14 µg/L | - |
| 50 | Wabedo Lake | Cass | A | 10.5 ft | 16 µg/L | - |