Cleanest Lakes in the US 2026: Top 50 by Water Quality

Of the 33,763 US lakes listed here, 5,873 carry enough nutrient and algae sampling to rank. The top 50 below draw from 8 states, led by Minnesota with 26 — deep, low-nutrient northern waters like Minnesota's Boundary Waters lakes and Wisconsin's spring-fed Northwoods lakes are over-represented at the top.

The cleanest lake on the index is Sunset Lake in Rutland County, VT — first on measured clarity and nutrients, with 36.1 feet of water clarity and phosphorus of 8.5 µg/L. Below that, the rest of the top 10 span 9.6 feet of Secchi between #1 and #10.

All readings come from EPA National Aquatic Resource Surveys and state monitoring programs (MN PCA, WI DNR). Lakes with fewer than three sampling visits are flagged as "limited data." Nutrient and algae readings describe ecology — they do not replace beach-specific E. coli advisories, which your state health department updates separately.

Top 9 Cleanest Lakes

Sunset Lake

Rutland County, Vermont · 36.1 ft clear

36.1 ft clearOligotrophic

Lake page →

Flaming Gorge Reservoir

Daggett County, Utah · 31.8 ft clear

31.8 ft clearOligotrophic

Lake page →

Caspian Lake

Orleans County, Vermont · 29.5 ft clear

29.5 ft clearOligotrophic

Lake page →

Clearwater Lake

Cook County, Minnesota · 29 ft clear

29 ft clearOligotrophic

Lake page →

Shadow Lake

Orleans County, Vermont · 28.9 ft clear

28.9 ft clearOligotrophic

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Maidstone Lake

Essex County, Vermont · 28.5 ft clear

28.5 ft clearOligotrophic

Lake page →

Lake Willoughby

Orleans County, Vermont · 28.2 ft clear

28.2 ft clearOligotrophic

Lake page →

Holland Lake

Dakota County, Minnesota · 27.9 ft clear

27.9 ft clearOligotrophic

Lake page →

Kerbs Lake

Otter Tail County, Minnesota · 27.7 ft clear

27.7 ft clearOligotrophic

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Rank	Lake	County	State	Clarity	Max Depth
1	Sunset Lake	Rutland	VT	36.1 ft	-
2	Flaming Gorge Reservoir	Daggett	UT	31.8 ft	-
3	Caspian Lake	Orleans	VT	29.5 ft	-
4	Clearwater Lake	Cook	MN	29 ft	65 ft
5	Shadow Lake	Orleans	VT	28.9 ft	-
6	Maidstone Lake	Essex	VT	28.5 ft	-
7	Lake Willoughby	Orleans	VT	28.2 ft	-
8	Holland Lake	Dakota	MN	27.9 ft	55 ft
9	Kerbs Lake	Otter Tail	MN	27.7 ft	-
10	Little Mcdonald Lake	Otter Tail	MN	26.5 ft	109 ft
11	Lake Elligo	Orleans	VT	26.2 ft	-
12	Coles Run Reservoir	Augusta	VA	25.8 ft	-
13	Forest Lake	Washington	VT	25.6 ft	-
14	Bad Medicine Lake	Becker	MN	25 ft	84 ft
15	Serpent Lake	Crow Wing	MN	25 ft	65 ft
16	Big Cormorant Lake	Becker	MN	24.8 ft	75 ft
17	Seymour Lake	Orleans	VT	24.6 ft	-
18	Echo Lake	Rutland	VT	24.3 ft	-
19	Big Blue Lake	Kalkaska	MI	24 ft	-
20	Lake Bomoseen	Rutland	VT	23.6 ft	-
21	Big Sand Lake	Hubbard	MN	23 ft	135 ft
22	Stony Lake	Cass	MN	23 ft	50 ft
23	Big Twin Lake	Kalkaska	MI	23 ft	-
24	Echo Lake	Orleans	VT	23 ft	-
25	Turtle Lake	Becker	MN	23 ft	73 ft
26	Belle Taine Lake	Hubbard	MN	22.8 ft	56 ft
27	Eagle Lake	Otter Tail	MN	22.6 ft	46 ft
28	Whitefish Lake	Flathead	MT	22 ft	-
29	West Sylvia Lake	Wright	MN	22 ft	97 ft
30	Berlin Pond	Washington	VT	21.7 ft	-
31	Lake Fairlee	Orange	VT	21.7 ft	-
32	Long Lake	Cass	MN	21.5 ft	115 ft
33	Lake Mirror	Washington	VT	21.3 ft	-
34	Round Lake	Sawyer	WI	21.1 ft	74 ft
35	Bearskin Lake	Cook	MN	21 ft	78 ft
36	Six Lake	Otter Tail	MN	21 ft	140 ft
37	East Sylvia Lake	Wright	MN	21 ft	78 ft
38	Harveys Lake	Caledonia	VT	21 ft	-
39	Geneva Lake	Walworth	WI	21 ft	135 ft
40	Swenson Lake	Beltrami	MN	20.7 ft	76 ft
41	Mayhew Lake	Cook	MN	20.6 ft	84 ft
42	Long Lake	Clearwater	MN	20.5 ft	80 ft
43	Ten Mile Lake	Cass	MN	20.5 ft	208 ft
44	Newark Pond	Caledonia	VT	20.4 ft	-
45	Beaver Lake	Carroll	AR	20.3 ft	-
46	Gilmore Lake	Hubbard	MN	20.3 ft	54 ft
47	Little Sand Lake	Hubbard	MN	20 ft	80 ft
48	Long Lake	Beltrami	MN	20 ft	87 ft
49	Big Fish Lake	Stearns	MN	20 ft	70 ft
50	Ossawinnamakee Lake	Crow Wing	MN	20 ft	63 ft

Where to stay near America's cleanest lakes

Planning a lake trip? Jump to live cabin, resort, and hotel availability on each top-ranked lake's page.

CSV

Top 500 Cleanest Lakes — Water Quality Dataset (2026)

The 500 top lakes across US lakes with nutrient and algae readings in one spreadsheet — water clarity, phosphorus, chlorophyll-a, trophic state, size, public access, and a link to each lake's page.

Frequently Asked Questions

Sunset Lake in Rutland County, VT, ranks first on measured clarity and nutrients. Its water clarity (Secchi depth) reads 36.1 feet, with phosphorus at 8.5 µg/L, from EPA and state agency sampling.

Each lake's nutrient and algae readings — total phosphorus, total nitrogen, chlorophyll-a, and turbidity — are shown beside the EPA National Lakes Assessment 2022 condition class for that lake's own ecoregion, so a reading is compared against the lakes it would naturally resemble. LakeQuality publishes no letter grade. 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. The readings cover nutrients and algae only. They are blind to mercury, PFAS and bacteria, so they are not a swimming clearance and not a fish-consumption clearance. A lake with limited sampling behind it cannot headline this table.

Not always. Water clarity correlates with low algae and low phosphorus — the same factors that drive harmful algal blooms — but Secchi does not measure E. coli, cyanotoxins, or a posted beach closure. Nutrient and algae readings are not a same-day clearance. Always check current swimming advisories before getting in.

Clean lakes share three traits: low nutrient inputs (especially phosphorus from septic, fertilizer, and farm runoff), good circulation and depth (deeper lakes resist warming and stratification), and protected forested shorelines that filter runoff. The cleanest lakes on this list tend to be deep, far from cropland, and surrounded by undeveloped land.

Clearest Water →Improving →Declining →Best Fishing →

More on clean water

Lake Water Quality Explained: What the Readings Mean

How nutrient and algae readings are read against EPA ecoregion condition classes, what each class means in the water, and why a clean reading is not a clearance.

Cleanest Small Lakes in America 2026

The cleanest U.S. lakes under 500 acres, ranked on measured nutrients, algae, and water clarity — with the size cutoff applied to the lake, not the sample.

How to Choose a Clean Lake for a Cabin or Weekend Trip

A practical checklist for picking a lake with good water quality — clarity, phosphorus, algae history, depth, and the data to check before you commit.