The State of Minnesota's Lakes 2026

Cleanest lakes in Minnesota

Highest combined water-quality score, 2026.

1. 1.ARainy Lake — Cass County13.9 ft clarity · 12 µg/L P · 2 µg/L chl-a
2. 2.ACrane Lake — Otter Tail County9.0 ft clarity · 15 µg/L P · 6 µg/L chl-a
3. 3.ALobster Lake — Douglas County13.0 ft clarity · 21 µg/L P · 4 µg/L chl-a
4. 4.AEast Fox Lake — Crow Wing County16.4 ft clarity · 10 µg/L P · 3 µg/L chl-a
5. 5.ADeep Portage Lake — Cass County15.4 ft clarity · 9 µg/L P · 2 µg/L chl-a
6. 6.AClearwater Lake — Cook County29.0 ft clarity · 4 µg/L P · 1 µg/L chl-a
7. 7.AClearwater Lake — Wright County9.8 ft clarity · 22 µg/L P · 6 µg/L chl-a
8. 8.AClearwater Lake — Clearwater County10.0 ft clarity · 16 µg/L P · 3 µg/L chl-a
9. 9.ALower Hay Lake — Crow Wing County18.5 ft clarity · 13 µg/L P · 3 µg/L chl-a
10. 10.ALatoka Lake — Douglas County19.0 ft clarity · 11 µg/L P · 2 µg/L chl-a

Most-polluted lakes

Lowest combined water-quality score among monitored lakes.

1. 1.FNorth Long Lake — Ramsey County2.5 ft clarity · 102 µg/L P · 31 µg/L chl-a
2. 2.FMud Lake — Hennepin County0.9 ft clarity · 150 µg/L P · 124 µg/L chl-a
3. 3.FRound Lake — Itasca County4.1 ft clarity · 67 µg/L P · 32 µg/L chl-a
4. 4.FPike Lake — Ramsey County2.3 ft clarity · 124 µg/L P · 54 µg/L chl-a
5. 5.FHorseshoe Lake — Stearns County4.0 ft clarity · 120 µg/L P · 45 µg/L chl-a
6. 6.FLong Lake — Kandiyohi County5.0 ft clarity · 92 µg/L P · 42 µg/L chl-a
7. 7.FLong Lake — Hennepin County3.3 ft clarity · 62 µg/L P · 32 µg/L chl-a
8. 8.FBig Swan Lake — Meeker County2.6 ft clarity · 87 µg/L P · 61 µg/L chl-a
9. 9.FUnnamed Lake — Meeker County0.7 ft clarity · 224 µg/L P · 85 µg/L chl-a
10. 10.FUnnamed Lake — Polk County2.0 ft clarity · 72 µg/L P · 51 µg/L chl-a

Worst algae hotspots

Highest measured chlorophyll-a (algae) concentration.

1. 1.NROlson Lake — Big Stone County384 µg/L chlorophyll-a
2. 2.FCowley Lake — Hennepin County344 µg/L chlorophyll-a
3. 3.NRDomeier Lake — Brown County332 µg/L chlorophyll-a
4. 4.NRUnnamed Lake — Brown County300 µg/L chlorophyll-a
5. 5.FAlice Lake — Otter Tail County254 µg/L chlorophyll-a
6. 6.FMaria Lake — Carver County250 µg/L chlorophyll-a
7. 7.FUhlenkolts Lake — Stearns County205 µg/L chlorophyll-a
8. 8.NRTalcot Lake — Cottonwood County193 µg/L chlorophyll-a
9. 9.FFountain Lake — Wright County174 µg/L chlorophyll-a
10. 10.NRClear Lake — Stevens County171 µg/L chlorophyll-a

Trending lakes

Improving

1. 1.ARainy Lake — Cass County
2. 2.ACrane Lake — Otter Tail County
3. 3.AEast Fox Lake — Crow Wing County
4. 4.ADeep Portage Lake — Cass County
5. 5.ALower Hay Lake — Crow Wing County
6. 6.ABig Lake — Carlton County
7. 7.APelican Lake — Crow Wing County
8. 8.ABirch Lake — Ramsey County

Declining

1. 1.FRound Lake — Itasca County
2. 2.FHorseshoe Lake — Stearns County
3. 3.FLong Lake — Stearns County
4. 4.FLong Lake — Kandiyohi County
5. 5.FLong Lake — Hennepin County
6. 6.FClear Lake — Meeker County
7. 7.FClear Lake — Waseca County
8. 8.FClear Lake — Jackson County