Cook County Lake Quality

Minnesota, 139 lakes, average grade A (Excellent)

Cook County has 139 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. On average, Cook County lakes grade an A. That puts it near the top of the Minnesota county ranking.

Many of the county's lakes are deep glacial basins — over 50 feet at their deepest point — which gives them thermal stratification and a buffer against summer warming. Clearwater Lake (grade A) is the cleanest in the county.

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Quick Answers for Cook County

Cleanest lakes in Cook County →Cleanest lakes in Minnesota →Safest swimming lakes in Minnesota →

Planning a trip? Check special fishing regulations for Clearwater Lake — or browse the full Minnesota regulations index.

Fishing in Cook County

Cook County Fishing Guide

Fish species and best-graded lakes in Cook County

DNR Reports (40)

Minnesota DNR LakeFinder resources for lakes in Cook County. browse all reports →

These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).

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Fisheries Lake Survey — West Twin
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — West Pike
Fisheries Lake Survey · MN DNR LakeFinder
—
Fisheries Lake Survey — Mountain
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Ward
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Two Island
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Trout
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Tom
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Crooked
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Tait
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Star
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — South
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Gull
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Sawbill
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Round
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Duncan
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Rog
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Rice
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Red Rock
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Portage
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Lizz
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Pine
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Pike
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Phoebe
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Peter
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Owl
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Ambush
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Mora
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Missouri
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Little John
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Mayhew
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Loon
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Long Island
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Little Saganaga
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Leo
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Kemo
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Karl
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Jasper
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Hungry Jack
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Horseshoe
Fisheries Lake Survey · MN DNR LakeFinder
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Fisheries Lake Survey — Homer
Fisheries Lake Survey · MN DNR LakeFinder

All Lakes in Cook County

139 lakes · 44 graded, 95 not rated44 graded lakes · 95 not rated, hidden

Include not-rated lakes (95)

#	Lake	Grade	Clarity	Phosphorus	Algae	Trophic	Max Depth	Access
1	AClearwater LakeCook	A	29 ft	4 µg/L	1.3 µg/L	No recent samples	65 ft	Carry-in
2	ABirch LakeCook	A	18 ft	8 µg/L	1.9 µg/L	No recent samples	69 ft	✓ Public
3	ARound LakeCook	A	16.5 ft	8.5 µg/L	1.6 µg/L	No recent samples	45 ft	✓ Public
4	APike LakeCook	A	17.4 ft	7 µg/L	2.6 µg/L	No recent samples	45 ft	✓ Public
5	AWest Twin LakeCook	A	9.8 ft	9 µg/L	3.5 µg/L	No recent samples	37 ft	✓ Public
6	ATrout LakeCook	A	18.4 ft	9 µg/L	1.3 µg/L	No recent samples	77 ft	✓ Public
7	APortage LakeCook	A	8.5 ft	9.5 µg/L	3.3 µg/L	No recent samples	55 ft	Carry-in
8	AGull LakeCook	A	15.5 ft	8.5 µg/L	2.5 µg/L	No recent samples	No recent samples	✓ Public
9	ACaribou LakeCook	A	6.9 ft	15 µg/L	6.2 µg/L	No recent samples	6 ft	✓ Public
10	ADevil Track LakeCook	A	7 ft	12 µg/L	5.3 µg/L	No recent samples	50 ft	✓ Public
11	APoplar LakeCook	A	10.2 ft	9 µg/L	3.3 µg/L	No recent samples	30 ft	Carry-in
12	ADeer Yard LakeCook	A	7.2 ft	15 µg/L	5.3 µg/L	No recent samples	20 ft	✓ Public
13	AElbow LakeCook	A	3.7 ft	18.5 µg/L	4.8 µg/L	No recent samples	9 ft	✓ Public
14	AHungry Jack LakeCook	A	18 ft	7 µg/L	2 µg/L	No recent samples	71 ft	✓ Public
15	ATom LakeCook	A	9 ft	8 µg/L	4.1 µg/L	No recent samples	35 ft	✓ Public
16	ATait LakeCook	A	7 ft	13 µg/L	3.3 µg/L	No recent samples	15 ft	✓ Public
17	ASea Gull LakeCook	A	14.3 ft	7 µg/L	2.7 µg/L	No recent samples	40 ft	✓ Public
18	AMayhew LakeCook	A	20.6 ft	5 µg/L	1.5 µg/L	No recent samples	84 ft	✓ Public
19	ALoon LakeCook	A	17.4 ft	5 µg/L	1.6 µg/L	No recent samples	202 ft	✓ Public
20	AGunflint LakeCook	A	16.5 ft	5.5 µg/L	2.6 µg/L	No recent samples	200 ft	✓ Public
21	AFlour LakeCook	A	18.2 ft	7 µg/L	2.4 µg/L	No recent samples	75 ft	✓ Public
22	ATwo Island LakeCook	A	9 ft	12 µg/L	3.4 µg/L	No recent samples	27 ft	✓ Public
23	ABearskin LakeCook	A	21 ft	6 µg/L	1.3 µg/L	No recent samples	78 ft	✓ Public
24	ATurtle Lake DeepCook	A	No recent samples	22 µg/L	2 µg/L	No recent samples	No recent samples	Not recorded
25	AMcfarland LakeCook	A	17 ft	8 µg/L	2.3 µg/L	No recent samples	8 ft	✓ Public
26	AWard LakeCook	A	5.6 ft	16.5 µg/L	5.3 µg/L	No recent samples	13 ft	✓ Public
27	AClara LakeCook	A	7.6 ft	15 µg/L	4 µg/L	No recent samples	15 ft	✓ Public
28	ASaganaga LakeCook	A	13 ft	7 µg/L	2.9 µg/L	No recent samples	No recent samples	Not recorded
29	AGreenwood LakeCook	A	15.1 ft	10 µg/L	2.6 µg/L	No recent samples	112 ft	✓ Public
30	ATaylor Lake DeepCook	A	10.6 ft	13 µg/L	3.5 µg/L	No recent samples	No recent samples	Not recorded
31	ATrout Lake DeepCook	A	10.7 ft	9.7 µg/L	4.3 µg/L	No recent samples	No recent samples	Not recorded
32	ATeal Lake DeepCook	A	4.1 ft	15.5 µg/L	5.7 µg/L	No recent samples	No recent samples	✓ Public
33	ALittle Lake DeepCook	A	4.9 ft	14 µg/L	3.9 µg/L	No recent samples	No recent samples	✓ Public
34	ANorth Lake DeepCook	A	No recent samples	7.7 µg/L	2.9 µg/L	No recent samples	No recent samples	Not recorded
35	AIron LakeCook	A	4.9 ft	18 µg/L	5.8 µg/L	No recent samples	19 ft	✓ Public
36	ALittle Iron LakeCook	A	4.2 ft	17.5 µg/L	5.5 µg/L	No recent samples	18 ft	✓ Public
37	CEast Twin LakeCook	C	6.2 ft	17 µg/L	7.9 µg/L	No recent samples	19 ft	✓ Public
38	CHelmer_nelson Pond DeepCook	C	2.5 ft	60 µg/L	2.9 µg/L	No recent samples	No recent samples	Not recorded
39	CBall Club LakeCook	C	9.1 ft	16.5 µg/L	7.6 µg/L	No recent samples	25 ft	✓ Public
40	CLoon Lake DeepCook	C	No recent samples	23 µg/L	7.6 µg/L	No recent samples	No recent samples	Not recorded
41	CCuffs Lake DeepCook	C	No recent samples	31 µg/L	8 µg/L	No recent samples	No recent samples	Not recorded
42	CDyers LakeCook	C	6.3 ft	21.5 µg/L	13.7 µg/L	No recent samples	23 ft	✓ Public
43	CSwamp Lake DeepCook	C	1.7 ft	27 µg/L	9.2 µg/L	No recent samples	No recent samples	Not recorded
44	DMt Maud LakeCook	D	3.4 ft	47 µg/L	16.8 µg/L	No recent samples	No recent samples	Not recorded
	NRAda LakeCook	NR	5.5 ft	No recent samples	No recent samples	No recent samples	13 ft	Carry-in
	NRHorseshoe LakeCook	NR	7.7 ft	No recent samples	No recent samples	No recent samples	26 ft	Carry-in
	NRStar LakeCook	NR	4.9 ft	No recent samples	No recent samples	No recent samples	13 ft	✓ Public
	NRCrooked LakeCook	NR	5.5 ft	No recent samples	No recent samples	No recent samples	66 ft	Carry-in
	NRRice LakeCook	NR	5.7 ft	17 µg/L	6.2 µg/L	No recent samples	10 ft	Carry-in
	NRCaribou LakeCook	NR	8.8 ft	No recent samples	No recent samples	No recent samples	26 ft	Carry-in
	NRHomer LakeCook	NR	6 ft	No recent samples	No recent samples	No recent samples	22 ft	✓ Public
	NREsther LakeCook	NR	9.5 ft	No recent samples	No recent samples	No recent samples	35 ft	✓ Public
	NRRed Rock LakeCook	NR	12 ft	No recent samples	No recent samples	No recent samples	64 ft	Carry-in
	NROnagon LakeCook	NR	6 ft	No recent samples	No recent samples	No recent samples	15 ft	✓ Public
	NREast Bearskin LakeCook	NR	14 ft	No recent samples	No recent samples	No recent samples	66 ft	✓ Public
	NRPine LakeCook	NR	16.9 ft	No recent samples	No recent samples	No recent samples	113 ft	Carry-in
	NROwl LakeCook	NR	13 ft	No recent samples	No recent samples	No recent samples	70 ft	Carry-in
	NRLeo LakeCook	NR	15 ft	No recent samples	No recent samples	No recent samples	28 ft	✓ Public
	NRDuncan LakeCook	NR	21.5 ft	No recent samples	No recent samples	No recent samples	130 ft	Carry-in
	NRRose LakeCook	NR	14.6 ft	No recent samples	No recent samples	No recent samples	130 ft	Carry-in
	NRLone LakeCook	NR	21 ft	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRLizz LakeCook	NR	9 ft	No recent samples	No recent samples	No recent samples	30 ft	Carry-in
	NRHolly LakeCook	NR	4.5 ft	No recent samples	No recent samples	No recent samples	6 ft	✓ Public
	NRCopper LakeCook	NR	7 ft	No recent samples	No recent samples	No recent samples	52 ft	Carry-in
	NRKemo LakeCook	NR	17 ft	No recent samples	No recent samples	No recent samples	65 ft	Carry-in
	NRLittle Saganaga LakeCook	NR	7 ft	No recent samples	No recent samples	No recent samples	150 ft	Carry-in
	NRPeter LakeCook	NR	22.5 ft	No recent samples	No recent samples	No recent samples	120 ft	Carry-in
	NRCanoe LakeCook	NR	20.5 ft	No recent samples	No recent samples	No recent samples	40 ft	Carry-in
	NRBrule LakeCook	NR	10 ft	No recent samples	No recent samples	No recent samples	78 ft	✓ Public
	NRChevans Lake YCook	NR	1.9 ft	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRJasper LakeCook	NR	12 ft	No recent samples	No recent samples	No recent samples	125 ft	Carry-in
	NRDutchman Lake DeepCook	NR	2.3 ft	31 µg/L	14.7 µg/L	No recent samples	No recent samples	✓ Public
	NRMt Maud Lake Mid BasinCook	NR	2.5 ft	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRCenter LakedeepCook	NR	1.4 ft	53 µg/L	52.7 µg/L	No recent samples	No recent samples	Not recorded
	NRSwede Lake DeepCook	NR	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRMt Maud Lake Beaver DamCook	NR	2.9 ft	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRChevans Lake DeepCook	NR	1.9 ft	17.5 µg/L	4.6 µg/L	No recent samples	No recent samples	Not recorded
	NRCenter LakelandingCook	NR	1.4 ft	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRHelmer_nelson Pond MiddleCook	NR	2.5 ft	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRDutchman LakelandingCook	NR	2.3 ft	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRChaser LakeCook	NR	1 ft	No recent samples	No recent samples	No recent samples	65 ft	Carry-in
	NRHelmer_nelson Pond InletCook	NR	2.3 ft	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRMt Maud Lake W_edge_basinCook	NR	2.5 ft	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRChester LakeCook	NR	11.9 ft	No recent samples	No recent samples	No recent samples	35 ft	✓ Public
	NRAlpine LakeCook	NR	12 ft	No recent samples	No recent samples	No recent samples	65 ft	Carry-in
	NRHelmer_nelson Pond East End Beaver HouseCook	NR	2.5 ft	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRHub LakeCook	NR	5.2 ft	No recent samples	No recent samples	No recent samples	No recent samples	Carry-in
	NRMesaba LakeCook	NR	10 ft	No recent samples	No recent samples	No recent samples	65 ft	Carry-in
	NRMt Maud Lake InletCook	NR	3.4 ft	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRGust LakeCook	NR	7 ft	No recent samples	No recent samples	No recent samples	6 ft	✓ Public
	NRTurtle Lake InletCook	NR	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRSwede Lake OutletCook	NR	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRSwede Lake InletCook	NR	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRTurtle Lake East EndCook	NR	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRMora LakeCook	NR	8.5 ft	No recent samples	No recent samples	No recent samples	40 ft	Carry-in
	NRTarry LakeCook	NR	13 ft	No recent samples	No recent samples	No recent samples	66 ft	Carry-in
	NRAlder LakeCook	NR	13.8 ft	8 µg/L	3.1 µg/L	No recent samples	72 ft	Carry-in
	NRBeth LakeCook	NR	11.1 ft	No recent samples	No recent samples	No recent samples	22 ft	Carry-in
	NRLittle Lake InletCook	NR	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	✓ Public
	NRPhoebe LakeCook	NR	7.5 ft	No recent samples	No recent samples	No recent samples	25 ft	Carry-in
	NRLittle Gunflint LakeCook	NR	16.2 ft	7 µg/L	1.3 µg/L	No recent samples	200 ft	✓ Public
	NRKarl LakeCook	NR	8 ft	No recent samples	No recent samples	No recent samples	70 ft	Carry-in
	NRDick LakeCook	NR	7.7 ft	10 µg/L	5.2 µg/L	No recent samples	12 ft	Carry-in
	NRAlton LakeCook	NR	13.5 ft	No recent samples	No recent samples	No recent samples	72 ft	Carry-in
	NRMissouri LakeCook	NR	4.1 ft	11 µg/L	2.8 µg/L	No recent samples	4 ft	✓ Public
	NRGogebic LakeCook	NR	13.8 ft	5 µg/L	1.7 µg/L	No recent samples	61 ft	Carry-in
	NRLittle Lake LandingCook	NR	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	✓ Public
	NRRog LakeCook	NR	19.6 ft	No recent samples	No recent samples	No recent samples	40 ft	Carry-in
	NRDavis LakeCook	NR	8.9 ft	No recent samples	No recent samples	No recent samples	64 ft	Carry-in
	NRElla LakeCook	NR	6 ft	4 µg/L	1.9 µg/L	No recent samples	No recent samples	Carry-in
	NRSouth LakeCook	NR	26 ft	No recent samples	No recent samples	No recent samples	140 ft	Carry-in
	NRSuperior LakeCook	NR	15.1 ft	4 µg/L	1.2 µg/L	No recent samples	No recent samples	✓ Public
	NRGabimichigami LakeCook	NR	11.5 ft	No recent samples	No recent samples	No recent samples	209 ft	Carry-in
	NRCuffs Lake LandingCook	NR	4.9 ft	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRSawbill LakeCook	NR	6.6 ft	No recent samples	No recent samples	No recent samples	45 ft	✓ Public
	NRWatap LakeCook	NR	9 ft	No recent samples	No recent samples	No recent samples	210 ft	Carry-in
	NRRove LakeCook	NR	9 ft	No recent samples	No recent samples	No recent samples	130 ft	✓ Public
	NREast Pike LakeCook	NR	12.2 ft	No recent samples	No recent samples	No recent samples	40 ft	Carry-in
	NRWest Pike LakeCook	NR	19 ft	No recent samples	No recent samples	No recent samples	120 ft	Carry-in
	NRLong Island LakeCook	NR	9.1 ft	No recent samples	No recent samples	No recent samples	85 ft	Carry-in
	NRCross Bay LakeCook	NR	7 ft	No recent samples	No recent samples	No recent samples	No recent samples	Carry-in
	NRLower George LakeCook	NR	3.5 ft	No recent samples	No recent samples	No recent samples	No recent samples	Carry-in
	NRGaskin LakeCook	NR	10.8 ft	No recent samples	No recent samples	No recent samples	82 ft	Carry-in
	NRPipe LakeCook	NR	10.5 ft	No recent samples	No recent samples	No recent samples	33 ft	Carry-in
	NRCrescent LakeCook	NR	8 ft	No recent samples	No recent samples	No recent samples	28 ft	✓ Public
	NRFrost LakeCook	NR	11 ft	No recent samples	No recent samples	No recent samples	88 ft	Carry-in
	NRTaylor Lake LandingCook	NR	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRNorth Lake LandingCook	NR	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRTrout Lake LandingCook	NR	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRLoon Lake InletCook	NR	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRLoon Lake LandingCook	NR	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRTeal Lake LandingCook	NR	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	✓ Public
	NRCuffs Lake InletCook	NR	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRSwamp Lake LandingCook	NR	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRTrout Lake InletCook	NR	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRSwamp Lake InletCook	NR	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRLittle Lake CulvertCook	NR	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	✓ Public
	NRLoon Lake OutletCook	NR	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	NRTurtle Lake West PondCook	NR	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded

NR = not rated: the monitoring record does not meet the evidence bar for a grade. That is EPA Integrated Reporting Category 3 (insufficient information), not a failing grade. How grading works.

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