A rocky, tree-lined Boundary Waters shoreline in evening light, the far shore reflected in calm water

Lake directory

Boundary Waters Lakes, Graded A–F

221lakes graded

Every Boundary Waters area lake we grade, ranked cleanest first. 12 lakes earn a confident Grade A; 209 rest on a single sample and are flagged. Tap a lake for its full report card — clarity trend, fish species, depth, and mercury-advisory status.

Reviewed by LakeQuality Editorial Team · Updated Aug 26, 2026

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All 221 lakes, cleanest first

#	Lake	County	Grade	Clarity	Area	Max depth
1	Burntside Lake	St. Louis	A	16 ft	7,314 acres	126 ft
2	Clearwater Lake	Cook	A	29 ft	462 acres	65 ft
3	Fall Lake	Lake	A	5.5 ft	2,258 acres	32 ft
4	Gunflint Lakelimited data	Cook	A	16.5 ft	4,009 acres	200 ft
5	Loon Lake	Cook	A	17.4 ft	1,095 acres	202 ft
6	Saganaga Lake	Cook	A	13 ft	-	-
7	Sea Gull Lake	Cook	A	14.3 ft	168 acres	40 ft
8	Bearskin Lake	Cook	A	21 ft	509 acres	78 ft
9	Big Lakelimited data	St. Louis	A	8.2 ft	1,904 acres	22 ft
10	Birch Lakelimited data	Cook	A	18 ft	236 acres	69 ft
11	Ed Shave Lakelimited data	St. Louis	A	11.5 ft	90 acres	17 ft
12	Farm Lake	Lake	A	5.5 ft	1,292 acres	56 ft
13	Fenske Lakelimited data	St. Louis	A	11.5 ft	108 acres	43 ft
14	Flour Lakelimited data	Cook	A	18.2 ft	330 acres	75 ft
15	Gull Lake	Cook	A	15.5 ft	-	-
16	Hungry Jack Lake	Cook	A	18 ft	474 acres	71 ft
17	Iron Lakelimited data	Cook	A	4.9 ft	122 acres	19 ft
18	Isabella Lakelimited data	Lake	A	4.4 ft	1,257 acres	19 ft
19	Little Iron Lakelimited data	Cook	A	4.2 ft	115 acres	18 ft
20	Mayhew Lake	Cook	A	20.6 ft	221 acres	84 ft
21	Mcfarland Lakelimited data	Cook	A	17 ft	40 acres	8 ft
22	Poplar Lake	Cook	A	10.2 ft	23 acres	30 ft
23	Portage Lakelimited data	Cook	A	8.5 ft	128 acres	55 ft
24	Round Lakelimited data	Cook	A	16.5 ft	154 acres	45 ft
25	Snowbank Lakelimited data	Lake	B	15.1 ft	4,655 acres	150 ft
26	East Twin Lakelimited data	St. Louis	C	4.9 ft	123 acres	22 ft
27	Everett Lakelimited data	St. Louis	C	7 ft	113 acres	15 ft
28	Meander Lakelimited data	St. Louis	C	13 ft	99 acres	25 ft
29	Alice Lakelimited data	Lake	NR	8.2 ft	1,469 acres	53 ft
30	Alton Lakelimited data	Cook	NR	13.5 ft	969 acres	72 ft
31	Basswood Lakelimited data	Lake	NR	9 ft	25,953 acres	111 ft
32	Brule Lakelimited data	Cook	NR	10 ft	4,327 acres	78 ft
33	Crooked Lakelimited data	Lake	NR	9 ft	10,360 acres	165 ft
34	Ensign Lakelimited data	Lake	NR	10 ft	1,411 acres	30 ft
35	Insula Lakelimited data	Lake	NR	7.5 ft	2,840 acres	63 ft
36	Kekekabic Lakelimited data	Lake	NR	19 ft	55 acres	130 ft
37	Knife Lakelimited data	Lake	NR	20 ft	105 acres	11 ft
38	Lac la Croix Lakelimited data	St. Louis	NR	8 ft	29,597 acres	168 ft
39	Little Saganaga Lakelimited data	Cook	NR	7 ft	1,627 acres	150 ft
40	Moose Lakelimited data	Lake	NR	13 ft	1,301 acres	65 ft
41	Ogishkemuncie Lakelimited data	Lake	NR	11.5 ft	762 acres	75 ft
42	Ottertrack Lakelimited data	Lake	NR	20 ft	113 acres	70 ft
43	Sawbill Lakelimited data	Cook	NR	6.6 ft	834 acres	45 ft
44	Thomas Lakelimited data	Lake	NR	14.2 ft	1,465 acres	110 ft
45	Ada Lakelimited data	Cook	NR	5.5 ft	23 acres	13 ft
46	Adventure Lakelimited data	Lake	NR	6.8 ft	47 acres	10 ft
47	Agamok Lakelimited data	Lake	NR	10 ft	-	-
48	Agnes Lakelimited data	St. Louis	NR	11 ft	1,045 acres	30 ft
49	Ahmakose Lakelimited data	Lake	NR	18 ft	43 acres	68 ft
50	Ahsub Lakelimited data	Lake	NR	16.5 ft	60 acres	78 ft
51	Alder Lakelimited data	Cook	NR	13.8 ft	529 acres	72 ft
52	Alpine Lakelimited data	Cook	NR	12 ft	909 acres	65 ft
53	Amoeber Lakelimited data	Lake	NR	18.8 ft	410 acres	110 ft
54	Annie Lakelimited data	Lake	NR	9 ft	19 acres	16 ft
55	Ashdick Lakelimited data	Lake	NR	13 ft	109 acres	50 ft
56	Ashigan Lakelimited data	Lake	NR	12.2 ft	153 acres	59 ft
57	Bear Trap Lakelimited data	St. Louis	NR	8.2 ft	121 acres	38 ft
58	Beth Lakelimited data	Cook	NR	11.1 ft	170 acres	22 ft
59	Bonnie Lakelimited data	Lake	NR	8.2 ft	105 acres	11 ft
60	Boot Lakelimited data	Lake	NR	16.5 ft	197 acres	83 ft
61	Boot Lakelimited data	St. Louis	NR	5.5 ft	323 acres	27 ft
62	Boulder Lakelimited data	Lake	NR	—	-	-
63	Canoe Lakelimited data	Cook	NR	20.5 ft	96 acres	40 ft
64	Caribou Lakelimited data	Cook	NR	8.8 ft	246 acres	26 ft
65	Cattyman Lakelimited data	Lake	NR	7 ft	17 acres	9 ft
66	Chaser Lakelimited data	Cook	NR	1 ft	213 acres	65 ft
67	Cherry Lakelimited data	Lake	NR	22 ft	19 acres	30 ft
68	Chester Lakelimited data	Cook	NR	11.9 ft	52 acres	35 ft
69	Chippewa Lakelimited data	Lake	NR	6.5 ft	-	-
70	Clark Lakelimited data	Lake	NR	—	1,162 acres	25 ft
71	Clearwater Lakelimited data	Lake	NR	18 ft	640 acres	46 ft
72	Copper Lakelimited data	Cook	NR	7 ft	37 acres	52 ft
73	Crab Lakelimited data	St. Louis	NR	—	420 acres	57 ft
74	Crooked Lakelimited data	Cook	NR	5.5 ft	244 acres	66 ft
75	Cross Bay Lakelimited data	Cook	NR	7 ft	-	-
76	Davis Lakelimited data	Cook	NR	8.9 ft	323 acres	64 ft
77	Disappointment Lakelimited data	Lake	NR	13.5 ft	894 acres	54 ft
78	Dix Lakelimited data	Lake	NR	14 ft	-	-
79	Duncan Lakelimited data	Cook	NR	21.5 ft	477 acres	130 ft
80	East Bearskin Lakelimited data	Cook	NR	14 ft	593 acres	66 ft
81	East Pike Lakelimited data	Cook	NR	12.2 ft	554 acres	40 ft
82	Eddy Lakelimited data	Lake	NR	17 ft	122 acres	95 ft
83	Ella Lakelimited data	Cook	NR	6 ft	-	-
84	Elton Lakelimited data	Lake	NR	5 ft	124 acres	53 ft
85	Ester Lakelimited data	Lake	NR	18.8 ft	374 acres	110 ft
86	Esther Lakelimited data	Cook	NR	9.5 ft	78 acres	35 ft
87	Fairy Lakelimited data	St. Louis	NR	7 ft	109 acres	19 ft
88	Finger Lakelimited data	St. Louis	NR	8.5 ft	272 acres	60 ft
89	Flash Lakelimited data	Lake	NR	9 ft	83 acres	24 ft
90	Found Lakelimited data	Lake	NR	10.8 ft	60 acres	38 ft
91	Four Lakelimited data	Lake	NR	8 ft	611 acres	25 ft
92	Fourtown Lakelimited data	Lake	NR	7 ft	323 acres	27 ft
93	Fraser Lakelimited data	Lake	NR	12.5 ft	695 acres	105 ft
94	Frog Lakelimited data	Lake	NR	10.5 ft	53 acres	38 ft
95	Frost Lakelimited data	Cook	NR	11 ft	284 acres	88 ft
96	Gabbro Lakelimited data	Lake	NR	4.3 ft	977 acres	50 ft
97	Gabimichigami Lakelimited data	Cook	NR	11.5 ft	1,186 acres	209 ft
98	Gaskin Lakelimited data	Cook	NR	10.8 ft	372 acres	82 ft
99	Ge-Be-on-Equat Lakelimited data	St. Louis	NR	10 ft	660 acres	55 ft
100	Gerund Lakelimited data	Lake	NR	9.5 ft	90 acres	85 ft
101	Gibson Lakelimited data	Lake	NR	7 ft	33 acres	24 ft
102	Gijikiki Lakelimited data	Lake	NR	20.5 ft	113 acres	70 ft
103	Gogebic Lakelimited data	Cook	NR	13.8 ft	62 acres	61 ft
104	Good Lakelimited data	Lake	NR	10 ft	175 acres	51 ft
105	Green Lakelimited data	St. Louis	NR	9 ft	160 acres	20 ft
106	Gun Lakelimited data	St. Louis	NR	9 ft	341 acres	57 ft
107	Gust Lakelimited data	Cook	NR	7 ft	143 acres	6 ft
108	Ham Lakelimited data	Lake	NR	6 ft	1,469 acres	53 ft
109	Hanson Lakelimited data	Lake	NR	18 ft	289 acres	100 ft
110	Hatchet Lakelimited data	Lake	NR	7 ft	127 acres	40 ft
111	Hazel Lakelimited data	Lake	NR	8 ft	-	-
112	Homer Lakelimited data	Cook	NR	6 ft	434 acres	22 ft
113	Horse Lakelimited data	Lake	NR	7 ft	715 acres	25 ft
114	Horseshoe Lakelimited data	Cook	NR	7.7 ft	188 acres	26 ft
115	Horseshoe Lakelimited data	Lake	NR	8 ft	205 acres	40 ft
116	Hub Lakelimited data	Cook	NR	5.2 ft	-	-
117	Hudson Lakelimited data	Lake	NR	8 ft	-	-
118	Ima Lakelimited data	Lake	NR	11 ft	742 acres	116 ft
119	Indiana Lakelimited data	Lake	NR	15.3 ft	143 acres	31 ft
120	Iron Lakelimited data	St. Louis	NR	5 ft	1,962 acres	64 ft
121	Jackfish Lakelimited data	Lake	NR	7 ft	-	-
122	Jasper Lakelimited data	Cook	NR	12 ft	246 acres	125 ft
123	Jenny Lakelimited data	Lake	NR	15.5 ft	102 acres	93 ft
124	Jitterbug Lakelimited data	Lake	NR	4.5 ft	28 acres	5 ft
125	Jordan Lakelimited data	Lake	NR	10.5 ft	142 acres	66 ft
126	Karl Lakelimited data	Cook	NR	8 ft	121 acres	70 ft
127	Kawasachong Lakelimited data	Lake	NR	4 ft	162 acres	11 ft
128	Kawishi Lakelimited data	Lake	NR	4.5 ft	372 acres	12 ft
129	Kek Lakelimited data	Lake	NR	19.5 ft	55 acres	130 ft
130	Kemo Lakelimited data	Cook	NR	17 ft	189 acres	65 ft
131	Kiana Lakelimited data	Lake	NR	13.8 ft	-	-
132	Kingfisher Lakelimited data	Lake	NR	13 ft	37 acres	42 ft
133	Koma Lakelimited data	Lake	NR	5 ft	250 acres	14 ft
134	Lake of the Cloudslimited data	Lake	NR	12 ft	29 acres	110 ft
135	Leo Lakelimited data	Cook	NR	15 ft	102 acres	28 ft
136	Link Lakelimited data	Lake	NR	10 ft	38 acres	34 ft
137	Little Gabbro Lakelimited data	Lake	NR	6.5 ft	148 acres	26 ft
138	Little Gunflint Lakelimited data	Cook	NR	16.2 ft	4,009 acres	200 ft
139	Little Long Lakelimited data	St. Louis	NR	21 ft	322 acres	45 ft
140	Little Vermilion Lakelimited data	St. Louis	NR	10 ft	116 acres	17 ft
141	Lizz Lakelimited data	Cook	NR	9 ft	23 acres	30 ft
142	Lone Lakelimited data	Cook	NR	21 ft	-	-
143	Long Island Lakelimited data	Cook	NR	9.1 ft	884 acres	85 ft
144	Low Lakelimited data	St. Louis	NR	8.7 ft	316 acres	40 ft
145	Lower George Lakelimited data	Cook	NR	3.5 ft	-	-
146	Lower Pauness Lakelimited data	St. Louis	NR	5.7 ft	171 acres	36 ft
147	Lunar Lakelimited data	Lake	NR	9.3 ft	62 acres	60 ft
148	Malberg Lakelimited data	Lake	NR	5.5 ft	398 acres	37 ft
149	Manomin Lakelimited data	Lake	NR	2 ft	409 acres	18 ft
150	Melon Lakelimited data	Lake	NR	8 ft	-	-
151	Mesaba Lakelimited data	Cook	NR	10 ft	213 acres	65 ft
152	Missionary Lakelimited data	Lake	NR	16.5 ft	99 acres	71 ft
153	Mora Lakelimited data	Cook	NR	8.5 ft	210 acres	40 ft
154	Mudro Lakelimited data	St. Louis	NR	—	94 acres	76 ft
155	Mueller Lakelimited data	Lake	NR	9 ft	24 acres	36 ft
156	N Br Kawishiwi R Lakelimited data	Lake	NR	6.2 ft	182 acres	13 ft
157	Neglige Lakelimited data	Lake	NR	11.3 ft	32 acres	58 ft
158	Newfound Lakelimited data	Lake	NR	12.8 ft	643 acres	45 ft
159	Newton Lakelimited data	Lake	NR	5 ft	516 acres	47 ft
160	Nibin Lakelimited data	St. Louis	NR	5.6 ft	776 acres	40 ft
161	Niki Lakelimited data	Lake	NR	7.7 ft	-	-
162	Nina Moose Lakelimited data	St. Louis	NR	2 ft	411 acres	6 ft
163	North Branch Kawishi Lakelimited data	Lake	NR	8.2 ft	182 acres	13 ft
164	North Hegman Lakelimited data	St. Louis	NR	6.5 ft	70 acres	30 ft
165	Onagon Lakelimited data	Cook	NR	6 ft	31 acres	15 ft
166	One Lakelimited data	Lake	NR	7.5 ft	846 acres	57 ft
167	Owl Lakelimited data	Cook	NR	13 ft	77 acres	70 ft
168	Oyster Lakelimited data	St. Louis	NR	6.6 ft	763 acres	130 ft
169	Pan Lakelimited data	Lake	NR	11 ft	-	-
170	Papoose Lakelimited data	Lake	NR	6 ft	-	-
171	Parent Lakelimited data	Lake	NR	18 ft	451 acres	50 ft
172	Peter Lakelimited data	Cook	NR	22.5 ft	282 acres	120 ft
173	Phoebe Lakelimited data	Cook	NR	7.5 ft	610 acres	25 ft
174	Pickle Lakelimited data	Lake	NR	12 ft	-	-
175	Pine Lakelimited data	Cook	NR	16.9 ft	2,122 acres	113 ft
176	Pipe Lakelimited data	Cook	NR	10.5 ft	285 acres	33 ft
177	Polly Lakelimited data	Lake	NR	11 ft	122 acres	95 ft
178	Polly Lakelimited data	Lake	NR	4.5 ft	485 acres	21 ft
179	Portage Lakelimited data	Lake	NR	13.3 ft	64 acres	45 ft
180	Rabbit Lakelimited data	Lake	NR	13.5 ft	117 acres	105 ft
181	Ramshead Lakelimited data	St. Louis	NR	—	553 acres	10 ft
182	Red Rock Lakelimited data	Cook	NR	12 ft	451 acres	64 ft
183	Rifle Lakelimited data	Lake	NR	4.8 ft	904 acres	37 ft
184	Rivalry Lakelimited data	Lake	NR	10 ft	153 acres	100 ft
185	Rocky Lakelimited data	St. Louis	NR	7 ft	120 acres	40 ft
186	Rog Lakelimited data	Cook	NR	19.6 ft	54 acres	40 ft
187	Rose Lakelimited data	Cook	NR	14.6 ft	477 acres	130 ft
188	Rove Lakelimited data	Cook	NR	9 ft	1,344 acres	130 ft
189	Sandpit Lakelimited data	Lake	NR	14 ft	61 acres	53 ft
190	Shell Lakelimited data	St. Louis	NR	9 ft	493 acres	15 ft
191	Sinneeg Lakelimited data	St. Louis	NR	11 ft	160 acres	32 ft
192	Skoota Lakelimited data	Lake	NR	13 ft	-	-
193	Skull Lakelimited data	Lake	NR	11 ft	29 acres	38 ft
194	South Farm Lakelimited data	Lake	NR	5 ft	564 acres	31 ft
195	South Hegman Lakelimited data	St. Louis	NR	8.5 ft	118 acres	55 ft
196	South Lakelimited data	Cook	NR	26 ft	1,145 acres	140 ft
197	Splash Lakelimited data	Lake	NR	8.5 ft	92 acres	18 ft
198	Spoon Lakelimited data	Lake	NR	13 ft	256 acres	85 ft
199	Square Lakelimited data	Lake	NR	5.5 ft	123 acres	7 ft
200	Strup Lakelimited data	Lake	NR	10 ft	1,689 acres	195 ft
201	Sucker Lakelimited data	Lake	NR	12 ft	25,953 acres	111 ft
202	Sunday Lakelimited data	St. Louis	NR	6.3 ft	-	-
203	Tarry Lakelimited data	Cook	NR	13 ft	244 acres	66 ft
204	Three Lakelimited data	Lake	NR	8 ft	904 acres	37 ft
205	Tin Can Mike Lakelimited data	Lake	NR	11 ft	145 acres	29 ft
206	Toe Lakelimited data	St. Louis	NR	13.5 ft	169 acres	57 ft
207	Toe Lakelimited data	Lake	NR	7.5 ft	122 acres	95 ft
208	Tofte Lakelimited data	Lake	NR	18.5 ft	134 acres	73 ft
209	Topaz Lakelimited data	Lake	NR	17.6 ft	410 acres	110 ft
210	Trader Lakelimited data	Lake	NR	7.7 ft	54 acres	10 ft
211	Trease Lakelimited data	St. Louis	NR	4.7 ft	97 acres	-
212	Triangle Lakelimited data	Lake	NR	12.3 ft	300 acres	43 ft
213	Trident Lakelimited data	Lake	NR	6.5 ft	93 acres	14 ft
214	Two Lakelimited data	Lake	NR	7.5 ft	516 acres	35 ft
215	Vera Lakelimited data	Lake	NR	18 ft	250 acres	55 ft
216	Wagosh Lakelimited data	St. Louis	NR	8 ft	42 acres	10 ft
217	Washte Lakelimited data	Lake	NR	12 ft	81 acres	7 ft
218	Watap Lakelimited data	Cook	NR	9 ft	1,993 acres	210 ft
219	West Pike Lakelimited data	Cook	NR	19 ft	788 acres	120 ft
220	Wind Lakelimited data	Lake	NR	9 ft	926 acres	32 ft
221	Wisini Lakelimited data	Lake	NR	10 ft	43 acres	68 ft

209 lakes are marked limited data — their grade rests on a single measurement and is excluded from our headline "cleanest" rankings.

Keep exploring

Entry points & permits

Quota permits by entry point

Why the water is so clean

The data story

Clearest lakes in Minnesota

Statewide clarity ranking

Where to stay near the Boundary Waters

Top-rated places to stay near the Boundary Waters

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Frequently Asked Questions

Among lakes with more than one measurement, the clearest is Clearwater Lake, with about 29 feet of visibility. Most interior lakes grade A or B; grades drop on developed edges and river-fed shallows.

It means the grade rests on a single water-quality sample. We flag these lakes and keep them out of "cleanest lake" headline rankings, because one reading can't capture a season. Treat a limited-data grade as a first indication, not a verdict.

Lakes are graded A to F on nutrients and algae — total phosphorus, total nitrogen, chlorophyll-a, and turbidity — measured against the EPA National Lakes Assessment 2022 condition classes for that lake's own ecoregion, so a lake is judged against the lakes it would naturally resemble. Water clarity (Secchi depth) is measured and shown in feet on every lake page but is not scored: EPA assigns no condition class to Secchi depth, and dark water can come from algae, from natural dissolved colour, or from suspended clay. Depth, fish, and recreation data are shown alongside but do not change the grade.

Data: EPA Water Quality Portal and the Minnesota DNR.