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LakeGrade

Which Lakes Have the Most Fish Species?

We analyzed fish survey data from state DNR records across 80 documented species. Some lakes are home to 15 or more species — true biodiversity hotspots that support everything from lake trout and muskellunge to panfish and rough fish.

Lakes with the highest species diversity tend to share several characteristics: large surface area providing diverse habitat, moderate to deep depth supporting both warm and cool water zones, and good water quality maintaining the dissolved oxygen these species need.

Top 25 Most Diverse Lakes

RankLakeCountyStateSpeciesGradeDepth
1Pepin LakePepinMN47F60 ft
2Lake St. CroixWashingtonMN36B78 ft
3Pool of Lake St. CroixWashingtonMN36C78 ft
4Pool on Lake St. Croix Downstream of I94 BridgeWashingtonMN36C78 ft
5Pool on Lake St. CroixWashingtonMN36C78 ft
6St. Croix 3.5 Mi. Downstream of E Chestnut St LakeWashingtonMN36C78 ft
7St. Croix LakeWashingtonMN36C78 ft
8St. Croix 1.5 Mi. Upstream of Point Douglas Dr LakeWashingtonMN36C78 ft
9St. Croix 0.3 Mi. Downstream of I LakeWashingtonMN36C78 ft
10Emily LakePopeMN26F6 ft
11Horseshoe LakeStearnsMN25D57 ft
12Zumbro LakeOlmstedMN24D43 ft
13Winona LakeWinonaMN24D38 ft
14Whitefish LakeCrow WingMN23A138 ft
15Long LakeStearnsMN23D35 ft
16Big Swan LakeMeekerMN23D32 ft
17Barrett LakeGrantMN23D28 ft
18Pokegama LakePineMN23F25 ft
19Little Spirit LakeJacksonMN23D8 ft
20Green LakeKandiyohiMN22A110 ft
21Cedar LakeAitkinMN22A105 ft
22Gull LakeCassMN22A80 ft
23Koronis LakeStearnsMN22C132 ft
24Big Sandy LakeAitkinMN22C84 ft
25Broadwater Bay LakeCassMN22A54 ft

What Makes a Lake Species-Rich?

  • Size — larger lakes have more shoreline niches, weed beds, rock structure, and open water habitat
  • Depth diversity — lakes with both shallow bays and deep basins support warm, cool, and cold water species simultaneously
  • Connected waterways — lakes with inlet/outlet streams allow species migration and population mixing
  • Water quality — clean lakes maintain oxygen at all depths, supporting the most demanding species

Full ranking: lakes with the most species → · Browse all 80 species →