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LakeQuality

Minnesota vs Wisconsin, Lake Water Quality Comparison

A data-driven comparison of lake water quality between the two premier lake states.

MinnesotaWisconsin
Total Lakes2,3331,354
Average GradeCB
Average Score2.482.58
Grade A Lakes68833
Grade B Lakes45537
Grade C Lakes307128
Grade D Lakes225126
Grade F Lakes2360
Oligotrophic (Cleanest)232127
Eutrophic (High Nutrient)568267
Fish Species Documented729
Lakes with Fish Data1,5851,116
Lakes with Invasives743857
Average Depth (ft)43 ft33 ft
Lakes with Depth Data1,8021,138
Improving Trend713499
Declining Trend828350
Ice Data Available1,0060

Analysis

Both Minnesota and Wisconsin are among the best lake states in the country. Minnesota has more total lakes and more ice data (the MN DNR has tracked ice-out dates for decades). Wisconsin's Northwoods region (Vilas, Oneida, Forest counties) has some of the cleanest lakes in either state.

For fishing, Wisconsin is considered the musky capital of the world, while Minnesota's walleye fisheries (Mille Lacs, Vermilion, Leech) are legendary. Both states have excellent smallmouth bass and panfish lakes.

Frequently Asked Questions

Does Minnesota or Wisconsin have cleaner lakes?

Minnesota has an average lake grade of C (score 2.48) while Wisconsin averages B (score 2.58). Wisconsin has slightly better average water quality, though both states have excellent lakes.

Which state has more lakes?

Minnesota has 2,333 graded lakes while Wisconsin has 1,354. Minnesota is known as the "Land of 10,000 Lakes" and has more monitored waterbodies.

Which state has more fish species?

Minnesota lakes have 72 documented species across 1,585 lakes, while Wisconsin has 9 species across 1,116 lakes.