What is the cleanest lake in St. Louis County, Minnesota?

Burntside Lake in St. Louis County is the highest-rated lake in St. Louis County, Minnesota with an EPA water quality grade of A and 16 feet of water clarity.

How are these rankings calculated?

Lakes are graded A through F on nutrients and algae — total phosphorus, nitrogen, chlorophyll-a, and turbidity — against EPA National Lakes Assessment 2022 condition classes for that lake’s ecoregion. Water clarity (Secchi depth) is measured and shown; it is not the letter. Lakes without enough recent samples are UNRATED, not given an F. Source data comes from the EPA Water Quality Portal.

Cleanest Lakes in St. Louis County, Minnesota

Burntside Lake in St. Louis County leads the rankings with a water quality grade of A and 16 ft of clarity. Below are the top 50 cleanest monitored lakes in St. Louis County, Minnesota, ranked by EPA water quality score.

Ranked List

#	Lake	County	Grade	Clarity	Phosphorus	Algae
1	Burntside Lake	St. Louis	A	16 ft	7 µg/L	2 µg/L
2	Bear Head Lake	St. Louis	A	11 ft	19.5 µg/L	3.6 µg/L
3	West Twin Lake	St. Louis	B	6.2 ft	18.5 µg/L	7.1 µg/L
4	Peary Lake	St. Louis	B	6.7 ft	20.2 µg/L	-
5	Sandy Lake	St. Louis	B	-	20.5 µg/L	-
6	Shoepack Lake	St. Louis	B	4.6 ft	19.8 µg/L	-
7	Little Sandy Lake	St. Louis	B	-	19 µg/L	-
8	Birch Lake	St. Louis	C	3.9 ft	21.5 µg/L	7.5 µg/L
9	Lost Lake	St. Louis	C	5.8 ft	110 µg/L	6.7 µg/L
10	Simian Lake	St. Louis	C	3.9 ft	33 µg/L	5.5 µg/L
11	Joe Martin Lake	St. Louis	C	14.5 ft	35.5 µg/L	2.3 µg/L
12	Heikkilla Lake	St. Louis	C	5 ft	24 µg/L	13.6 µg/L
13	Strand Lake	St. Louis	D	3.5 ft	44 µg/L	10.9 µg/L
14	Fishmouth Lake	St. Louis	NR	-	-	-
15	McDivitt Lake	St. Louis	NR	-	-	-
16	Weir Lake	St. Louis	NR	-	-	-
17	Wiyapka Lake	St. Louis	NR	-	-	-
18	Tooth Lake	St. Louis	NR	-	-	-
19	Lucille Lake	St. Louis	NR	-	-	-
20	Johnson Lake	St. Louis	NR	-	-	-
21	Spring Lake	St. Louis	NR	-	-	-
22	Franklin Lake	St. Louis	NR	-	-	-
23	Marion Lake	St. Louis	NR	-	-	-
24	Long Lake	St. Louis	NR	-	-	-
25	Gannon Lake	St. Louis	NR	-	-	-
26	Bluebird Lake	St. Louis	NR	-	-	-
27	Moose Lake	St. Louis	NR	-	-	-
28	Little Johnson Lake	St. Louis	NR	-	-	-
29	Amundsen Lake	St. Louis	NR	-	-	-
30	Corner Lake	St. Louis	NR	-	-	-
31	Namakan Lake	St. Louis	NR	-	-	-
32	Pearl Lake	St. Louis	NR	-	-	-
33	Moose Lake	St. Louis	NR	-	-	-
34	Bell Lake	St. Louis	NR	-	-	-
35	Swan Lake	St. Louis	NR	-	-	-
36	Chub Lake	St. Louis	NR	-	-	-
37	South Bog Lake	St. Louis	NR	-	-	-
38	Elephant Lake	St. Louis	NR	-	-	-
39	Silver Lake	St. Louis	NR	-	-	-
40	Bug Lake	St. Louis	NR	-	-	-
41	Kjostad Lake	St. Louis	NR	-	-	-
42	Clear Lake	St. Louis	NR	-	-	-
43	Myrtle Lake	St. Louis	NR	-	-	-
44	Carlson Lake	St. Louis	NR	-	-	-
45	Olive Lake	St. Louis	NR	-	-	-
46	Maude Lake	St. Louis	NR	-	-	-
47	Picket Lake	St. Louis	NR	-	-	-
48	Finstad Lake	St. Louis	NR	-	-	-
49	Gustafson Lake	St. Louis	NR	-	-	-
50	Bootleg Lake	St. Louis	NR	-	-	-

Ranked List

More Answers for St. Louis County, Minnesota