Missouri's Cleanest Lake: Sherwood Lake (Warren County)

The single cleanest lake in Missouri is Sherwood Lake (Warren County, MO), ranked first on its measured clarity and nutrients in the 2026 sampling record. Cleanliness here is measured by Secchi depth (clarity), total phosphorus, and chlorophyll-a — all sourced from EPA Water Quality Portal and state agency sampling, shown as reported. The full top 25 ranked list appears below.

The "cleanest" ranking on LakeQuality is built from the measured nutrients and algae — phosphorus and chlorophyll-a read against EPA National Lakes Assessment 2022 ecoregion classes. Secchi clarity is shown and used only as a tiebreak. The cleanest Missouri lake on the current data is Sherwood Lake (Warren County, MO).

The top of the cleanest-lakes list is dominated by deep, glacial, cold-water basins — the same basins that carry the lowest nutrient readings overall. The pattern is not coincidence: depth and watershed land-use are the dominant inputs to water-clarity and nutrient-loading both.

Rank	Lake	County	Clarity	Phosphorus	Chlorophyll-a	Area
1	Sherwood Lake (Warren County, MO)	Warren	5.9 ft	14.3 µg/L	4.4 µg/L	145 acres
2	Lake Taneycomo	Taney	8.7 ft	13.5 µg/L	1.1 µg/L	-
3	Fox Valley Lake	Clark	8.5 ft	16.5 µg/L	3.6 µg/L	96 acres
4	Bull Shoals Lake	Taney	8.1 ft	10 µg/L	4 µg/L	-
5	Lake Shayne-Terre du Lac Lakes	Washington	11.1 ft	5.2 µg/L	1.2 µg/L	51 acres
6	Lake Konstanz	Warren	7.7 ft	7 µg/L	1.6 µg/L	19 acres
7	Lake Capri	St. Francois	16.3 ft	5.7 µg/L	0.9 µg/L	112 acres
8	Innsbrook Lake	Warren	5.2 ft	17 µg/L	5 µg/L	-
9	Weatherby Lake	Platte	6.2 ft	16 µg/L	5.9 µg/L	186 acres
10	Table Rock L. Ab. Carter Br. Lake	Barry	6.8 ft	8.5 µg/L	4.3 µg/L	-
11	Council Bluff Lake	Iron	13.1 ft	5.7 µg/L	1.3 µg/L	-
12	Bowling Green Lake	Pike	5.5 ft	24.6 µg/L	5.1 µg/L	45 acres
13	Lake Taneycomo	Taney	8.9 ft	15.8 µg/L	1.2 µg/L	-
14	Lake Taneycomo	Taney	12.6 ft	14.5 µg/L	0.9 µg/L	-
15	Lake Wauwanoka	Jefferson	12.9 ft	8 µg/L	1.7 µg/L	-
16	Fellows Lake	Greene	7.2 ft	11.8 µg/L	3.4 µg/L	812 acres
17	Alpine Lake	Warren	12.6 ft	7 µg/L	1.5 µg/L	325 acres
18	Castlenovo Lake	Warren	6 ft	16.8 µg/L	2.9 µg/L	10 acres
19	Aspen Lake Along Southern Arm	Warren	3.8 ft	20.8 µg/L	5.3 µg/L	146 acres
20	Timberline Lakes	St. Francois	14.3 ft	5.5 µg/L	1.6 µg/L	42 acres
21	Lincoln Lake	Lincoln	5.7 ft	12.7 µg/L	3.6 µg/L	48 acres
22	Lake Buteo	Johnson	5.6 ft	20 µg/L	4 µg/L	8 acres
23	Lake Taneycomo Ab. Bee Cr. Arm	Taney	13.3 ft	13 µg/L	1.1 µg/L	-
24	Brookfield Lake	Linn	4.4 ft	19.7 µg/L	4.9 µg/L	106 acres
25	Rock Lake Village Lake	Johnson	4.3 ft	16 µg/L	4.8 µg/L	27 acres

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New nutrient and algae samples can move a lake up or down this ranking. Unsubscribe anytime.

All-states list →Clearest lakes in Missouri (by Secchi clarity) →Minnesota version →Wisconsin version →Illinois version →Best swimming lakes in Missouri →All Missouri lakes →

Clearest lakes in Missouri by water clarity

“Clearest” ranks by Secchi depth — how far you can see into the water — which can differ from the combined cleanliness score above. The clearest water in Missouri is Lake Capri at 16.3 ft of Secchi visibility.

1. Lake Capri — 16.3 ft, St. Francois County
2. Oasis Ranch Upper Lake — 14.4 ft, Audrain County
3. Timberline Lakes — 14.3 ft, St. Francois County
4. Lake Marseilles-Terre du Lac Lakes — 14.1 ft, St. Francois County
5. Oasis Ranch Lake — 14.1 ft, Audrain County

See the full clearest-lakes ranking for Missouri →

Frequently Asked Questions

What is the cleanest lake in Missouri?

Sherwood Lake (Warren County, MO) ranks first on measured clarity and nutrients in the 2026 Missouri sampling record. 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. Cleanliness here means a low nutrient load and little algae, measured directly from EPA and state DNR samples; where two lakes tie on nutrients and algae, the deeper Secchi reading ranks first.

Where in Missouri has the cleanest water?

Missouri's clearest waters are concentrated in deeper, lower-nutrient glacial basins with forested or low-agriculture watersheds. Among the current top-ranked lakes above, counties like Warren, Taney, and St. Francois produce the highest-scoring lakes.

What is the clearest lake in Missouri?

Lake Capri is the clearest lake in Missouri by water clarity, with a Secchi depth of 16.3 feet — the deepest transparency in our 2026 dataset. "Clearest" ranks by Secchi depth (how far you can see into the water) specifically, while "cleanest" combines clarity with phosphorus and chlorophyll-a. See our full clearest-lakes ranking for Missouri for the top 25 by Secchi clarity.

Are these lakes safe to swim in?

Not on these readings alone. Clarity and nutrient readings are not a swimming clearance: they do not measure E. coli, cyanotoxins, or a posted beach closure, and a lake with low chlorophyll-a can still bloom. Always check current posted advisories before swimming: water quality changes seasonally, especially in late summer when blue-green algae bloom risk peaks.

How is this ranking calculated?

Lakes are ranked on phosphorus, chlorophyll-a and clarity as measured by EPA and state agency sampling, read against EPA National Lakes Assessment 2022 condition classes for that lake’s ecoregion, not a Missouri-only 0–100 average. Water clarity is shown beside the nutrient readings. Lakes with limited sampling do not headline the table.

What are the top 5 cleanest lakes in the US?

There is no single national ranking of cleanest lakes — each state agency uses different metrics. Crater Lake (Oregon) is widely cited as the clearest US lake, with Secchi depths over 30 m. Lake Tahoe and Lake Superior are also top-tier nationally. Within Missouri, the 25 lakes ranked above have the lowest nutrient and algae readings in our 2026 dataset.

How we rank cleanest lakes

Cleanliness here means three things working together:

Secchi clarity — how deep you can see into the water (in feet). Greater depth = clearer water = lower suspended sediment and algae.
Total phosphorus — the nutrient that fuels algae. Lower phosphorus levels mean less algae growth potential.
Chlorophyll-a — the green pigment in algae. Direct measurement of how much algae is currently in the water.

Each signal is normalized against Missouri state norms and combined into a single 0–100 score. The lakes above are sorted by that combined score.Full methodology →

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.

Where to stay near Missouri's cleanest lakes

Compare cabins, resorts, and rentals around Sherwood Lake (Warren County, MO) and the other lakes in this ranking, with live availability and prices for your trip. Each pin on the map is one of the ranked lakes above.

Top-rated places to stay near Sherwood Lake (Warren County, MO)

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Source: EPA National Aquatic Resource Surveys, 2026.