Otter Tail County Lake Quality

Minnesota, 97 lakes, average grade B (Good)

Otter Tail County has 97 graded lakes, enough that within-county variation matters as much as the county average. Some are deep glacial basins, others are shallow agricultural-watershed waters, and the grade distribution reflects that mix. The county-wide average lands at B — solid water quality with most lakes carrying clear summer transparency and low-to-moderate phosphorus.

A meaningful share of Otter Tail's lakes break 50 feet of depth, which matters because deep lakes hold cooler water all summer and resist the resuspended-sediment problems that plague shallow basins. The county's best-graded lake is Pelican Lake (A).

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Quick Answers for Otter Tail County

Cleanest lakes in Otter Tail County →Cleanest lakes in Minnesota →Safest swimming lakes in Minnesota →

Planning a trip? Check special fishing regulations for Pelican Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Minnesota regulations index.

DNR Reports (248)

Minnesota DNR LakeFinder resources for lakes in Otter Tail County. Showing 12 most recent — browse all reports →

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Fisheries Lake Survey — Wright
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Wimer
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — West Silent
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — West McDonald
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — West Lost
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — West Leaf
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — West Battle
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Wall
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Walker
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Leek (Trowbridge)
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Tonseth
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Ten Mile
Fisheries Lake Survey · MN DNR LakeFinder

All Lakes in Otter Tail County

Rank	Lake	Grade	Clarity	Max Depth	Phosphorus
1	Pelican Lake	A	16.1 ft	55 ft	15 µg/L
2	Unnamed Lake	A	15.1 ft	95 ft	9 µg/L
3	Otter Lake	A	18 ft	64 ft	-
4	Eagle Lake	A	22.6 ft	46 ft	5 µg/L
5	Star Lake	A	16.7 ft	94 ft	13 µg/L
6	Fish Lake	A	17.8 ft	69 ft	12 µg/L
7	Big Mcdonald Lake	A	16.4 ft	46 ft	11 µg/L
8	Bass Lake	A	16.9 ft	-	14.5 µg/L
9	Lizzie Lake	A	16.4 ft	66 ft	13 µg/L
10	Devil'S Lake	A	15 ft	67 ft	13 µg/L
11	West Battle Lake	A	18.2 ft	108 ft	8 µg/L
12	Stuart Lake	A	16.1 ft	49 ft	12 µg/L
13	Little Mcdonald Lake	A	26.9 ft	109 ft	7 µg/L
14	Elbow Lake	A	18.5 ft	46 ft	11 µg/L
15	Scalp Lake	A	20 ft	90 ft	8 µg/L
16	West Silent Lake	A	18 ft	58 ft	8 µg/L
17	Rose Lake	A	15 ft	137 ft	-
18	Sybil Lake	A	20 ft	74 ft	9 µg/L
19	Kerbs Lake	A	27.7 ft	-	7 µg/L
20	Six Lake	A	20.2 ft	140 ft	7 µg/L
21	East Silent Lake	A	19.4 ft	48 ft	8 µg/L
22	Jewett Lake	A	17.1 ft	75 ft	14.5 µg/L
23	Mule Lake	A	17.1 ft	31 ft	8 µg/L
24	West Mcdonald Lake	A	16.2 ft	62 ft	-
25	Round Lake	A	11.6 ft	24 ft	18 µg/L
26	Long Lake	A	11.8 ft	128 ft	19.5 µg/L
27	Long Lake	A	12.1 ft	88 ft	19.5 µg/L
28	Long Lake	A	10.8 ft	73 ft	15 µg/L
29	Marion Lake	A	11 ft	62 ft	18 µg/L
30	East Loon Lake	A	13.5 ft	105 ft	12 µg/L
31	Pickerel Lake	A	14.1 ft	78 ft	12 µg/L
32	Silver Lake	A	11.3 ft	43 ft	15 µg/L
33	Clitherall Lake	A	14.3 ft	69 ft	9 µg/L
34	Swan Lake	A	12.1 ft	44 ft	17.5 µg/L
35	Blanche Lake	A	12.5 ft	64 ft	11 µg/L
36	Trowbridge Lake	A	11 ft	76 ft	16 µg/L
37	East Battle Lake	A	13.1 ft	87 ft	12 µg/L
38	Little Pelican Lake	A	11.5 ft	25 ft	19 µg/L
39	Otter Tail Lake	A	12.1 ft	120 ft	16 µg/L
40	Franklin Lake	A	13.1 ft	48 ft	17 µg/L
41	Wimer Lake	A	10.2 ft	58 ft	17.5 µg/L
42	Pebble Lake	A	13 ft	62 ft	16.5 µg/L
43	Boedigheimer Lake	A	10.2 ft	26 ft	18.5 µg/L
44	Leek Lake	A	11 ft	-	15 µg/L
45	Paul Lake	A	13.3 ft	81 ft	15 µg/L
46	Tonseth Lake	B	10 ft	27 ft	-
47	Deer Lake	B	11.5 ft	26 ft	21 µg/L
48	Lida Lake	B	13.5 ft	58 ft	21 µg/L
49	Prairie Lake	B	8.9 ft	22 ft	18 µg/L
50	Hook Lake	B	10.5 ft	-	-
51	East Lost Lake	B	12.5 ft	26 ft	-
52	Crystal Lake	B	10.2 ft	55 ft	20 µg/L
53	Crane Lake	B	9 ft	43 ft	17 µg/L
54	Alice Lake	B	14.5 ft	39 ft	-
55	Ethel Lake	B	14.6 ft	64 ft	-
56	Ten Mile Lake	B	13.6 ft	51 ft	24 µg/L
57	South Turtle Lake	B	14.1 ft	35 ft	20 µg/L
58	Belmont Lake	B	13.5 ft	34 ft	-
59	Otter Tail River Lake	B	11 ft	55 ft	-
60	Nelson Lake	B	10 ft	-	20 µg/L
61	Fiske Lake	B	13 ft	26 ft	-
62	Wright Lake	B	13.7 ft	32 ft	-
63	Iverson Lake	B	13.8 ft	18 ft	-
64	Hoot Lake	B	11.7 ft	20 ft	-
65	Round Lake	B	7.9 ft	36 ft	22 µg/L
66	Round Lake	B	4.3 ft	-	6.5 µg/L
67	Dead Lake	B	9.5 ft	65 ft	20 µg/L
68	Little Pine Lake	B	9.5 ft	63 ft	26 µg/L
69	Big Pine Lake	B	7 ft	76 ft	27 µg/L
70	Walker Lake	B	7.5 ft	29 ft	26.5 µg/L
71	Wall Lake	B	8.5 ft	34 ft	21 µg/L
72	Rush Lake	B	6.9 ft	68 ft	27.5 µg/L
73	West Leaf Lake	B	7.5 ft	55 ft	22 µg/L
74	Hoffman Lake	B	8.5 ft	20 ft	25 µg/L
75	East Leaf Lake	B	7.9 ft	43 ft	23 µg/L
76	Spitzer Lake	B	7 ft	33 ft	25 µg/L
77	Graham Lake	B	8.4 ft	34 ft	25.5 µg/L
78	Unnamed Lake	C	3.9 ft	-	25 µg/L
79	Stalker Lake	C	6.6 ft	95 ft	22 µg/L
80	Indian Lake	C	8.5 ft	37 ft	-
81	West Lost Lake	C	7.2 ft	16 ft	-
82	Buchanan Lake	C	5.2 ft	42 ft	22 µg/L
83	Bass Lake	C	5.9 ft	36 ft	40 µg/L
84	Berger Lake	C	5 ft	-	40 µg/L
85	Tamarac Lake	C	6.4 ft	11 ft	31.5 µg/L
86	Orwell Lake	C	4.1 ft	25 ft	54 µg/L
87	Mason Lake	C	3 ft	108 ft	21 µg/L
88	Long Lake	D	3 ft	-	37.5 µg/L
89	Unnamed Lake	D	4.9 ft	-	-
90	Clear Lake	D	6.3 ft	29 ft	-
91	Peterson Lake	D	5.9 ft	69 ft	-
92	Sewell Lake	D	5.5 ft	52 ft	-
93	North Turtle Lake	D	3.8 ft	19 ft	63 µg/L
94	Mud Lake	D	1.3 ft	-	87 µg/L
95	Mud Lake	F	1.6 ft	-	-
96	Unnamed Lake	F	1.3 ft	-	-
97	Alice Lake	F	0.5 ft	-	-

Source: EPA National Aquatic Resource Surveys, 2026.