Updated August 2026
Where to Swim: Safe Swimming Lakes Near You
Find a clean, safe lake to swim in, with E. coli bacteria testing surfaced where the EPA has enough samples to grade it. Use your location to find the closest safe swim lakes, or browse the top 50 across our 38-state dataset below.
- Grade A–B water quality
- Chlorophyll-a below 10 µg/L
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Related: Cleanest lakes → Swimming safety guide →
| Rank | Lake | County | State | Grade | Swim Safety | Clarity | Algae | Area |
|---|---|---|---|---|---|---|---|---|
| 1 | Rainy Lake | Cass | MN | A | Low algae | 13.9 ft | 1.8 µg/L | 129 acres |
| 2 | Crane Lake | Otter Tail | MN | A | Low algae | 9 ft | 6.4 µg/L | 350 acres |
| 3 | Lobster Lake | Douglas | MN | A | Low algae | 13 ft | 3.6 µg/L | 1,334 acres |
| 4 | East Fox Lake | Crow Wing | MN | A | Low algae | 16.4 ft | 2.7 µg/L | 241 acres |
| 5 | Deep Portage Lake | Cass | MN | A | Low algae | 15.4 ft | 1.6 µg/L | 129 acres |
| 6 | Clearwater Lake | Cook | MN | A | Low algae | 29 ft | 1.3 µg/L | 462 acres |
| 7 | Clearwater Lake | Wright | MN | A | Low algae | 9.8 ft | 6.3 µg/L | 3,187 acres |
| 8 | Clearwater Lake | Clearwater | MN | A | Low algae | 10 ft | 3.2 µg/L | 999 acres |
| 9 | Lower Hay Lake | Crow Wing | MN | A | Low algae | 18.5 ft | 2.7 µg/L | 700 acres |
| 10 | Latoka Lake | Douglas | MN | A | Low algae | 19 ft | 2.2 µg/L | 767 acres |
| 11 | Big Cedar Lake-North Site-Near West Bend | Washington | WI | A | Low algae | 11.8 ft | 3.6 µg/L | 937 acres |
| 12 | Big Cedar Lake-South Site-Near West Bend | Washington | WI | A | Low algae | 12.6 ft | 2.4 µg/L | 937 acres |
| 13 | Green Lake | Green Lake | WI | A | Low algae | 13.5 ft | 4.4 µg/L | 7,920 acres |
| 14 | Lake Beulah | Walworth | WI | A | Low algae | 10 ft | 2.5 µg/L | 812 acres |
| 15 | Okauchee Lake | Waukesha | WI | A | Low algae | 11.5 ft | 3.9 µg/L | 1,210 acres |
| 16 | Geneva Lake | Walworth | WI | A | Bacteria B | 21 ft | 2.1 µg/L | 5,401 acres |
| 17 | Powers Lake | Kenosha | WI | A | Low algae | 10 ft | 3.4 µg/L | 451 acres |
| 18 | Lac Courte Oreilles Lake | Sawyer | WI | A | Low algae | 12.2 ft | 1.7 µg/L | 5,139 acres |
| 19 | Whitefish Lake | Sawyer | WI | A | Low algae | 13.5 ft | 1.6 µg/L | 800 acres |
| 20 | Round Lake | Sawyer | WI | A | Low algae | 21.1 ft | 0.9 µg/L | 3,294 acres |
| 21 | Lake Calumet | Cook | IL | A | Low algae | 4.1 ft | 5.4 µg/L | 0 acres |
| 22 | Chippewa Lake Northeast Basin; Chippewa Township | Mecosta | MI | A | Low algae | 12.8 ft | 3.3 µg/L | - |
| 23 | Windover Lake South Basin; Freeman Township | Clare | MI | A | Low algae | 15 ft | 2.4 µg/L | - |
| 24 | Moon Lake Central Basin; Watersmeet Township | Gogebic | MI | A | Low algae | 18 ft | 3.2 µg/L | - |
| 25 | West Twin Lake East Basin; Albert Township | Montmorency | MI | A | Low algae | 13 ft | 1 µg/L | - |
| 26 | Eagle Lake West Central Basin; Ontwa Township | Cass | MI | A | Low algae | 6.3 ft | 4.7 µg/L | - |
| 27 | East Twin Lake South Central Basin; Albert Township | Montmorency | MI | A | Low algae | 10 ft | 4.1 µg/L | - |
| 28 | Brooks Lake | Leelanau | MI | A | Low algae | 9 ft | 4.8 µg/L | - |
| 29 | Indian Lake Central Basin; Brady Township | Kalamazoo | MI | A | Low algae | 9.5 ft | 3.5 µg/L | - |
| 30 | Sunset Lake West Central Basin; Bates Township | Iron | MI | A | Low algae | 15.5 ft | 1.9 µg/L | - |
| 31 | Big Bass Lake North Basin; Elk Township | Lake | MI | A | Low algae | 14 ft | 5.3 µg/L | - |
| 32 | West Okoboji Lake | Dickinson | IA | A | Bacteria A · advisory | 15.7 ft | 2.3 µg/L | - |
| 33 | Dale Maffitt Reservoir | Dallas | IA | A | Low algae | 9.8 ft | 2.1 µg/L | 230 acres |
| 34 | Blue Pit Lake | Cerro Gordo | IA | A | Low algae | 17.1 ft | 2.4 µg/L | - |
| 35 | Ada Hayden Heritage Park Lake | Story | IA | A | Low algae | 6.8 ft | 5.2 µg/L | - |
| 36 | Nine Eagles Lake | Decatur | IA | A | Bacteria advisory | 11 ft | 3.3 µg/L | 59 acres |
| 37 | Little Sioux Park Lake | Woodbury | IA | A | Bacteria A | 5.7 ft | 5.7 µg/L | - |
| 38 | Rudd Lake | Floyd | IA | A | Low algae | 8.1 ft | 4.5 µg/L | - |
| 39 | Slipbluff Lake | Decatur | IA | A | Low algae | 9 ft | 4.5 µg/L | 18 acres |
| 40 | Lacey Keosauqua Lake | Van Buren | IA | A | Low algae | 7.1 ft | 4.7 µg/L | 23 acres |
| 41 | Yenruogis Pond | Keokuk | IA | A | Low algae | 9.9 ft | 6.2 µg/L | - |
| 42 | Queneska Island Lake | Essex | NY | A | Low algae | 17.4 ft | 3.4 µg/L | - |
| 43 | South Lake | Herkimer | NY | A | Low algae | — | 1.1 µg/L | 499 acres |
| 44 | West Pond | Herkimer | NY | A | Low algae | — | 3.3 µg/L | - |
| 45 | Squash Pond | Herkimer | NY | A | Low algae | — | 2 µg/L | - |
| 46 | Sherwood Lake | Warren | MO | A | Low algae | 5.9 ft | 4.4 µg/L | 145 acres |
| 47 | Lake Taneycomo @ Rockaway Beach | Taney | MO | A | Low algae | 8.7 ft | 1.1 µg/L | - |
| 48 | Fox Valley Lake | Clark | MO | A | Low algae | 8.5 ft | 3.6 µg/L | 96 acres |
| 49 | Table Rock Lk. Into Main Channel From Dam Lake | Stone | MO | A | Low algae | 7.2 ft | 4.5 µg/L | 43,100 acres |
| 50 | Clearwater Lake | Wayne | MO | A | Low algae | 5.7 ft | 3.7 µg/L | - |
Frequently Asked Questions
How do you know if a lake is safe to swim?
Three signals matter most: water clarity (Secchi depth — clearer water has less suspended sediment and pathogens), chlorophyll-a (low values mean low algae density), and posted advisories from the state DNR or county health department. Lakes here all have grade A or B, chlorophyll-a below 10 µg/L, and pass our combined safety filter — but always check posted advisories the day you visit.
What is the 80/20 rule in swimming?
The 80/20 rule is a swim-training concept (80% easy aerobic work, 20% high intensity), unrelated to water quality. For lake-swimming safety, the relevant rule is the EPA recreational water guideline: total bacteria below 235 colonies per 100 mL for primary contact recreation.
What lakes are you not allowed to swim in?
Most US lakes allow swimming, but specific lakes may be closed seasonally for harmful algal blooms (HABs), elevated bacteria, or storm runoff. State DNRs and county health departments post advisories. Some reservoirs prohibit swimming year-round (drinking water sources, hazardous bottom conditions, restricted access). The lakes ranked here are all open public-access lakes with consistently safe water quality.
What are the risks of swimming in a lake?
The main risks are: (1) blue-green algae blooms (cyanobacteria) which produce toxins that cause skin irritation, gastrointestinal illness, or worse if swallowed; (2) bacterial contamination after heavy rain (E. coli from agricultural or sewage runoff); (3) underwater hazards like submerged rocks, weeds, or sudden depth changes. Swimmer safety: never swim alone, check advisories, avoid swimming after heavy rain, and stay out of visibly green or scummy water.
Can you get sick from swimming in a lake?
Yes — though it's rare in well-monitored lakes. The most common illnesses are gastrointestinal (from swallowing water with E. coli or other bacteria), skin rashes (from blue-green algae toxins), and ear infections. Swim in lakes with grade A or B water, avoid swallowing water, rinse off after swimming, and check posted advisories. The lakes ranked above are filtered for low algae and good clarity.