What are mesotrophic lakes in Minnesota?

577 mesotrophic lakes in Minnesota. Moderate nutrients, good water quality.

What does mesotrophic mean?

Moderate nutrients, good water quality.

Mesotrophic Lakes in Minnesota

Most well-managed working lakes register as mesotrophic — the band that balances productivity with clarity. 577 lakes in Minnesota sit in the mesotrophic band. About 29% are deep (50+ ft); the rest are shallower basins where watershed management keeps nutrients from pushing the system into eutrophy.

Mesotrophic lakes tend to grade B or C on our A–F scale — the productive-but-clear band lines up with the middle of the letter grades.

#	Lake	County	Grade	Clarity	Depth	TSI
1	Crane Lake	Otter Tail	A	9 ft	43 ft	46
2	Lobster Lake	Douglas	A	13 ft	65 ft	44
3	Clearwater Lake	Wright	A	9.8 ft	73 ft	47
4	Clearwater Lake	Crow Wing	A	13 ft	54 ft	41
5	Clearwater Lake	Clearwater	A	10 ft	65 ft	43
6	Little Birch Lake	Todd	A	13 ft	89 ft	43
7	North Long Lake	Crow Wing	A	15.1 ft	97 ft	40
8	Mud Lake	Becker	A	12.5 ft	34 ft	46
9	Big Lake	Beltrami	A	9.7 ft	35 ft	45
10	Big Lake	Carlton	A	10 ft	25 ft	43
11	Big Lake	Sherburne	A	13.6 ft	48 ft	42
12	Big Lake	St. Louis	A	8.2 ft	22 ft	45
13	Pelican Lake	Otter Tail	A	16.4 ft	55 ft	40
14	Birch Lake	Ramsey	A	5.9 ft	-	47
15	Birch Lake	Wright	A	15 ft	52 ft	42
16	Birch Lake	Cass	A	14 ft	45 ft	41
17	Round Lake	Crow Wing	A	13.5 ft	51 ft	42
18	Round Lake	Otter Tail	A	11.2 ft	24 ft	45
19	Round Lake	Becker	A	10 ft	69 ft	44
20	Round Lake	Anoka	A	8.9 ft	-	46
21	Whitefish Lake	Crow Wing	A	14.4 ft	138 ft	40
22	Whitefish Lake	Beltrami	A	12.5 ft	30 ft	42
23	Horseshoe Lake	Crow Wing	A	14.4 ft	56 ft	40
24	Horseshoe Lake	Cass	A	8.9 ft	12 ft	44
25	Horseshoe Lake	Isanti	A	3.5 ft	-	47
26	Farm Lake	Lake	A	5.5 ft	56 ft	47
27	Washburn Lake	Cass	A	14.1 ft	111 ft	40
28	Long Lake	Stearns	A	13.5 ft	28 ft	44
29	Long Lake	Kandiyohi	A	10.5 ft	46 ft	43
30	Long Lake	Otter Tail	A	12.3 ft	128 ft	44
31	Long Lake	Hubbard	A	11.2 ft	135 ft	42
32	Long Lake	Otter Tail	A	12.1 ft	88 ft	45
33	Long Lake	Beltrami	A	10 ft	83 ft	45
34	Long Lake	Otter Tail	A	11.6 ft	73 ft	44
35	Dead Lake	Otter Tail	A	10.2 ft	65 ft	46
36	Unnamed Lake	Crow Wing	A	6.6 ft	-	47
37	Unnamed Lake	Nicollet	A	5.6 ft	35 ft	48
38	Unnamed Lake	Sherburne	A	13 ft	43 ft	44
39	Maple Lake	Douglas	A	14.1 ft	78 ft	41
40	West Twin Lake	Cook	A	9.8 ft	37 ft	41
41	Shallow Lake	Hubbard	A	8.2 ft	10 ft	42
42	Detroit Lake	Becker	A	14 ft	89 ft	42
43	Sallie Lake	Becker	A	13 ft	50 ft	45
44	Deer Lake	Beltrami	A	11 ft	42 ft	44
45	Deer Lake	Otter Tail	A	12.3 ft	26 ft	45
46	Deer Lake	Itasca	A	8.9 ft	50 ft	46
47	Deer Lake	Hubbard	A	12.8 ft	9 ft	42
48	Chippewa Lake	Douglas	A	14.8 ft	95 ft	41
49	Twin Lake	Washington	A	13 ft	-	41
50	Otter Lake	Ramsey	A	11.5 ft	21 ft	44
51	Lida Lake	Otter Tail	A	14 ft	58 ft	45
52	Five Island Lake	Itasca	A	13 ft	33 ft	41
53	Big Spunk Lake	Stearns	A	10 ft	38 ft	43
54	Florida Lake	Kandiyohi	A	12.3 ft	40 ft	44
55	Clear Lake	Aitkin	A	15 ft	24 ft	41
56	Clear Lake	Washington	A	14 ft	27 ft	42
57	Garden Lake	Lake	A	5 ft	55 ft	48
58	Marion Lake	Dakota	A	7 ft	21 ft	47
59	Sullivan Lake	Morrison	A	10.8 ft	57 ft	44
60	Emerald Lake	Beltrami	A	9.5 ft	-	42
61	Vermont Lake	Douglas	A	14.1 ft	59 ft	41
62	Eagle Lake	Hubbard	A	11.2 ft	77 ft	44
63	Eagle Lake	Kandiyohi	A	6.9 ft	67 ft	49
64	Darling Lake	Douglas	A	14 ft	62 ft	43
65	Mantrap Lake	Hubbard	A	12 ft	-	44
66	Ida Lake	Douglas	A	16.4 ft	106 ft	40
67	Ida Lake	Becker	A	12.1 ft	20 ft	46
68	Ida Lake	Wright	A	13.1 ft	60 ft	42
69	Star Lake	Otter Tail	A	17 ft	94 ft	40
70	Upper Maple Lake	Wright	A	17.2 ft	76 ft	41
71	Fish Lake	Chisago	A	9.4 ft	57 ft	43
72	Sand Lake	Itasca	A	13.2 ft	60 ft	42
73	Little Pine Lake	Crow Wing	A	10 ft	36 ft	46
74	Norway Lake	Cass	A	6.9 ft	12 ft	48
75	Union Lake	Polk	A	15 ft	-	40
76	Snail Lake	Ramsey	A	11 ft	30 ft	45
77	Shell Lake	Becker	A	7.3 ft	16 ft	48
78	Andrusia Lake	Beltrami	A	15.1 ft	60 ft	41
79	Green Lake	Kandiyohi	A	14.1 ft	110 ft	42
80	Green Lake	Beltrami	A	12 ft	-	40
81	Upper Gull Lake	Cass	A	9.5 ft	54 ft	47
82	Little Toad Lake	Becker	A	15 ft	65 ft	44
83	Leech Lake	Cass	A	12.5 ft	-	40
84	Bass Lake	Crow Wing	A	13 ft	27 ft	45
85	Bass Lake	Wright	A	13.5 ft	34 ft	41
86	Bass Lake	Mahnomen	A	13.1 ft	26 ft	41
87	Bass Lake	Becker	A	12.8 ft	48 ft	43
88	Island Lake	Cass	A	15.5 ft	45 ft	42
89	Island Lake	Becker	A	15 ft	38 ft	42
90	Island Lake	Hubbard	A	10.5 ft	65 ft	46
91	Island Lake	Cass	A	8.2 ft	-	46
92	Island Lake	Clearwater	A	14.1 ft	58 ft	41
93	Moose Lake	Wright	A	14.4 ft	43 ft	40
94	Moose Lake	Itasca	A	8 ft	52 ft	48
95	Crooked Lake	Stearns	A	15.5 ft	35 ft	40
96	Crooked Lake	Douglas	A	14 ft	35 ft	45
97	Crooked Lake	Lake	A	3 ft	4 ft	48
98	Crooked Lake	Cass	A	12 ft	74 ft	42
99	Portage Lake	Cook	A	8.5 ft	55 ft	42
100	Portage Lake	Crow Wing	A	11.5 ft	37 ft	42

All mesotrophic lakes →Wisconsin version →Illinois version →Michigan version →Iowa version →Ohio version →Pennsylvania version →New York version →Missouri version →Indiana version →North Dakota version →South Dakota version →Florida version →Colorado version →North Carolina version →Vermont version →Texas version →Oregon version →Arkansas version →Oklahoma version →Kansas version →Nebraska version →Nevada version →Arizona version →Idaho version →Montana version →New Mexico version →Tennessee version →Alabama version →Virginia version →Kentucky version →Utah version →Washington version →Wyoming version →Georgia version →Massachusetts version →Ontario version →Québec version →Nova Scotia version →British Columbia version →Newfoundland and Labrador version →All Minnesota lakes →

Source: EPA National Aquatic Resource Surveys, 2026.