Grade B Lakes, Good

1,338 lakes (24% of all graded lakes)

B-grade lakes are the workhorses: clean enough for swimming, productive enough for a real fishery. 1,338 lakes earn a B; Minnesota (582) and Wisconsin (370) hold the largest shares.

The bracket leans mesotrophic — workable, productive, with stable clarity through most of the season but a real susceptibility to extra nutrient inputs. Roughly 15% of the B-grade lakes are deep waters; the rest are shallow basins with low nutrient inputs.

A B C D F

1,338

Total Lakes

States Covered

MN 582WI 370MI 220MO 63NY 41ND 31IL 19IA 8IN 4

Lake	County	State	Clarity	Depth	Fish
Horseshoe Lake	Cass	MN	8.9 ft	12 ft	0
Fish Lake	Chisago	MN	9.4 ft	57 ft	13
Leech Lake	Cass	MN	12.5 ft	-	0
Big Marine Lake	Washington	MN	12 ft	-	0
Silver Lake	Cass	MN	13 ft	20 ft	5
Little Big Lake	Beltrami	MN	9.3 ft	35 ft	17
Alice Lake	Itasca	MN	8.5 ft	65 ft	12
Sugar Lake	Itasca	MN	8.4 ft	22 ft	13
Third Lake	Carlton	MN	8.5 ft	-	0
Blooms Lake	Chisago	MN	6.9 ft	41 ft	0
Pat Martin Lake	Carlton	MN	6.6 ft	-	0
North Lindstrom Lake	Chisago	MN	6.9 ft	29 ft	13
Swift Lake	Cass	MN	8.5 ft	52 ft	13
Steamboat Bay Lake	Cass	MN	9.8 ft	150 ft	18
Lily Lake	Washington	MN	10.5 ft	51 ft	10
Little Horseshoe Lake	Chisago	MN	7.5 ft	43 ft	0
Upper Sucker Lake	Cass	MN	10.8 ft	25 ft	12
Six Mile Lake	Cass	MN	11.5 ft	68 ft	16
White Rock Lake	Washington	MN	7.5 ft	-	0
Wood Pile Lake	Washington	MN	10 ft	-	0
Sunset Lake	Washington	MN	9.5 ft	17 ft	11
Pine Tree Lake	Washington	MN	8.5 ft	-	8
Edith Lake	Washington	MN	8.2 ft	43 ft	0
Sunrise Lake	Chisago	MN	8.4 ft	21 ft	10
Little Lac Courte Oreilles Lake	Sawyer	WI	12 ft	46 ft	6
Sand Lake	Sawyer	WI	10 ft	50 ft	6
Gurno Lake	Sawyer	WI	10 ft	27 ft	5
Back Bay Deep Lake	Chippewa	MI	8.2 ft	-	0
Lake Taneycomo @ Rockaway Beach	Taney	MO	8.7 ft	-	0
Fox Valley Lake	Clark	MO	8.5 ft	-	0
Table Rock Lk. Into Main Channel From Dam Lake	Stone	MO	7.2 ft	-	0
Lake Konstanz	Warren	MO	7.7 ft	-	0
Bull Shoals Lake	Taney	MO	8.1 ft	-	0
Table Rock L. Ab. Carter Br. Lake	Barry	MO	6.8 ft	-	0
Lake Taneycomo	Taney	MO	8.9 ft	-	0
Fellows Lake	Greene	MO	7.2 ft	-	0
Stockton Lake by Dam	Cedar	MO	7.9 ft	-	0
Table Rock Lk. Btwn Campbell Point Rd And Hendrickson School Rd Lake	Stone	MO	6.9 ft	-	0
Cole Lake	Jefferson	MO	18.5 ft	-	0
Ripley County Lake	Ripley	MO	6.6 ft	-	0
Lake Nehai Tonkayea	Chariton	MO	8 ft	-	0
Lake Marie	Mercer	MO	7.8 ft	-	0
Table Rock Lake	Stone	MO	7.3 ft	-	0
Table Rock L. @ Mouth of James R. Arm Lake	Stone	MO	7.9 ft	-	0
North Bethany City Reservoir	Harrison	MO	10.5 ft	-	0
Port Perry Lake South Arm	Perry	MO	9.5 ft	-	0
Port Perry Lake North Arm	Perry	MO	7.4 ft	-	0
Quill Lake	St. Louis	MN	11.5 ft	46 ft	4
Loiten Lake	St. Louis	MN	11.5 ft	49 ft	3
O'Leary Lake	St. Louis	MN	10.7 ft	52 ft	9
Beast Lake	St. Louis	MN	10.2 ft	66 ft	2
Lobster Lake	Douglas	MN	13 ft	65 ft	18
Big Birch Lake	Todd	MN	12.5 ft	81 ft	18
Round Lake	Aitkin	MN	14.5 ft	27 ft	11
Round Lake	Aitkin	MN	14.5 ft	59 ft	15
Round Lake	Anoka	MN	8.9 ft	-	0
Minnetonka Lake	Hennepin	MN	10 ft	113 ft	18
Horseshoe Lake	Todd	MN	10 ft	24 ft	11
Horseshoe Lake	Itasca	MN	10.5 ft	25 ft	13
Cotton Lake	Becker	MN	11.5 ft	28 ft	15
Long Lake	Otter Tail	MN	12.3 ft	128 ft	16
Long Lake	Todd	MN	10.1 ft	63 ft	16
Long Lake	Todd	MN	14 ft	-	0
Long Lake	St. Louis	MN	12.5 ft	33 ft	8
Long Lake	Aitkin	MN	10.8 ft	116 ft	16
Long Lake	Stearns	MN	14 ft	46 ft	11
Dead Lake	Otter Tail	MN	10.2 ft	65 ft	18
West Twin Lake	Cook	MN	9.8 ft	37 ft	2
Tonseth Lake	Otter Tail	MN	10 ft	27 ft	12
Jordan Lake	Lake	MN	10.5 ft	66 ft	0
Twin Lake	Crow Wing	MN	13.5 ft	-	0
Fraser Lake	Lake	MN	12.5 ft	105 ft	0
Otter Lake	Stearns	MN	9 ft	51 ft	13
Otter Lake	Ramsey	MN	11.5 ft	21 ft	12
Pirz Lake	Stearns	MN	12 ft	-	0
Florida Lake	Kandiyohi	MN	12.3 ft	40 ft	18
Clear Lake	St. Louis	MN	11 ft	24 ft	9
Prairie Lake	Otter Tail	MN	8.9 ft	22 ft	15
Emerald Lake	Beltrami	MN	9.5 ft	-	0
Eagle Lake	Crow Wing	MN	9.5 ft	-	0
Kenney Lake	Crow Wing	MN	13.5 ft	55 ft	0
Ida Lake	Becker	MN	12.1 ft	20 ft	14
Sallie Lake	Becker	MN	13 ft	50 ft	16
Hook Lake	Otter Tail	MN	10.5 ft	-	0
Big Lake	Beltrami	MN	9.7 ft	35 ft	17
Big Lake	St. Louis	MN	8.2 ft	22 ft	8
Bass Lake	Itasca	MN	13.5 ft	76 ft	19
Bass Lake	Becker	MN	7.9 ft	28 ft	9
Crooked Lake	Douglas	MN	14 ft	35 ft	12
Mille Lacs Lake	Aitkin	MN	10 ft	42 ft	21
Cedar Lake	Wright	MN	13.6 ft	47 ft	11
Cedar Lake	Wright	MN	14.3 ft	108 ft	16
Ima Lake	Lake	MN	11 ft	116 ft	0
Pelican Lake	Stearns	MN	13.5 ft	46 ft	14
Fairy Lake	Todd	MN	14.2 ft	37 ft	13
Lawrence Lake	Cass	MN	9.8 ft	71 ft	16
Mud Lake	Becker	MN	12.5 ft	34 ft	16
Unnamed Lake	Sherburne	MN	13 ft	43 ft	7
Unnamed Lake	St. Louis	MN	11.5 ft	-	0
Unnamed Lake	Stearns	MN	10 ft	-	0

Showing 100 of 1,338 Grade B lakes.

Frequently Asked Questions

How many lakes have a grade of B?

There are 1,338 Grade B (Good) lakes across the 12 states LakeQuality covers, led by Minnesota (582) and Wisconsin (370). This represents 24% of all graded lakes.

What does a Grade B mean?

Grade B means good water quality with clear water (Secchi depth 10-15 ft), low phosphorus (20-30 µg/L), and low algae. Safe for swimming and supports diverse fisheries.

Featured Grade B Lakes

Horseshoe Lake

Cass County, MN · 8.9 ft clarity

Fish Lake

Chisago County, MN · 9.4 ft clarity

Leech Lake

Cass County, MN · 12.5 ft clarity

Big Marine Lake

Washington County, MN · 12 ft clarity

Silver Lake

Cass County, MN · 13 ft clarity

Little Big Lake

Beltrami County, MN · 9.3 ft clarity

Source: EPA National Aquatic Resource Surveys, 2026.