Cleanest Lakes in Minnesota & Wisconsin

The top 50 lakes ranked by overall water quality grade. Grades are based on water clarity (Secchi depth in feet), phosphorus levels, and chlorophyll-a (algae) concentration using Metropolitan Council standards.

Rank	Lake	County	State	Grade	Clarity	Max Depth
1	East Fox Lake	Crow Wing	MN	A	16.1 ft	65 ft
2	Deep Portage Lake	Cass	MN	A	15.4 ft	105 ft
3	Little Wabana Lake	Itasca	MN	A	23.8 ft	57 ft
4	Clearwater Lake	Cook	MN	A	30 ft	65 ft
5	Clearwater Lake	Lake	MN	A	18 ft	46 ft
6	Lower Hay Lake	Crow Wing	MN	A	19 ft	100 ft
7	Latoka Lake	Douglas	MN	A	19 ft	108 ft
8	Bad Medicine Lake	Becker	MN	A	25 ft	84 ft
9	Big Sugar Bush Lake	Becker	MN	A	17 ft	42 ft
10	Pelican Lake	Otter Tail	MN	A	16.1 ft	55 ft
11	Fullers Lake: East Basin	Beltrami	MN	A	49.2 ft	—
12	Birch Lake	Wright	MN	A	15 ft	52 ft
13	Birch Lake	Cook	MN	A	18 ft	69 ft
14	Birch Lake	Unknown	MN	A	15 ft	34 ft
15	Round Lake	Aitkin	MN	A	15.3 ft	59 ft
16	Round Lake	Cook	MN	A	16.5 ft	45 ft
17	Round Lake	Beltrami	MN	A	59.1 ft	38 ft
18	Pike Lake	Cook	MN	A	17.8 ft	45 ft
19	Pike Lake	St. Louis	MN	A	18 ft	60 ft
20	Whitefish Lake	Crow Wing	MN	A	15.1 ft	138 ft
21	Horseshoe Lake	Cass	MN	A	21 ft	51 ft
22	Long Lake	Clearwater	MN	A	20 ft	80 ft
23	Long Lake	Cass	MN	A	21.8 ft	115 ft
24	Long Lake	Beltrami	MN	A	20 ft	87 ft
25	Long Lake	Becker	MN	A	20 ft	61 ft
26	Long Lake	Cass	MN	A	16.8 ft	37 ft
27	Long Lake	Beltrami	MN	A	45.9 ft	—
28	Long Lake	Itasca	MN	A	16.7 ft	72 ft
29	Long Lake	Itasca	MN	A	16.9 ft	85 ft
30	Dead Lake	Hubbard	MN	A	16 ft	34 ft
31	Unnamed Lake	Otter Tail	MN	A	15.1 ft	95 ft
32	Maple Lake	Itasca	MN	A	15.3 ft	39 ft
33	West Twin Lake	Crow Wing	MN	A	19.8 ft	—
34	Sunshine Lake	St. Louis	MN	A	20 ft	37 ft
35	Shallow Lake	Itasca	MN	A	16.4 ft	85 ft
36	Trout Lake	Itasca	MN	A	15.5 ft	135 ft
37	Trout Lake	Itasca	MN	A	18 ft	157 ft
38	Trout Lake	Cook	MN	A	19 ft	77 ft
39	Chippewa Lake	Douglas	MN	A	15.1 ft	95 ft
40	Otter Lake	Otter Tail	MN	A	18 ft	64 ft
41	Eddy Lake	Lake	MN	A	16.5 ft	95 ft
42	Cowdry Lake	Douglas	MN	A	17 ft	52 ft
43	Ossawinnamakee Lake	Crow Wing	MN	A	20 ft	63 ft
44	Clear Lake	Crow Wing	MN	A	18 ft	63 ft
45	Clear Lake	Aitkin	MN	A	16 ft	24 ft
46	Clear Lake	Itasca	MN	A	14.9 ft	30 ft
47	Bear Lake	Lake	MN	A	17.4 ft	31 ft
48	Emerald Lake	Beltrami	MN	A	31.2 ft	—
49	Blue Lake	Hubbard	MN	A	17.4 ft	84 ft
50	Blue Lake	Crow Wing	MN	A	19 ft	48 ft