Recently Monitored Lakes
The 100 most recently sampled lakes in our dataset. Sample dates come from the EPA Water Quality Portal, which aggregates data from state DNR, USGS, tribal, and citizen-science monitoring networks. New samples appear here as data is processed (typically a multi-month lag from collection to public release).
| # | Lake | County | State | Grade | Clarity | Depth | Last Sampled |
|---|---|---|---|---|---|---|---|
| 1 | Green Lake | Green Lake | Wisconsin | C | 13.1 ft | 236 ft | 2025-12-22 |
| 2 | Geneva Lake | Walworth | Wisconsin | A | 20.7 ft | 135 ft | 2025-12-12 |
| 3 | Kusel Lake | Waushara | Wisconsin | A | 36.9 ft | 29 ft | 2025-11-30 |
| 4 | Sandy Lake | Marquette | Wisconsin | A | 26.2 ft | - | 2025-11-28 |
| 5 | Shadow Lake | Waupaca | Wisconsin | A | 39.4 ft | 41 ft | 2025-11-26 |
| 6 | Mirror Lake | Waupaca | Wisconsin | A | 36.1 ft | 43 ft | 2025-11-26 |
| 7 | Green Lake East Basin | Green Lake | Wisconsin | B | 11.8 ft | 236 ft | 2025-11-24 |
| 8 | Tahkodah Lake | Bayfield | Wisconsin | A | 32.8 ft | - | 2025-11-24 |
| 9 | North Lake | Waukesha | Wisconsin | A | 29.5 ft | 78.4 ft | 2025-11-24 |
| 10 | School Section Lake | Waukesha | Wisconsin | A | 16.7 ft | - | 2025-11-23 |
| 11 | White Lake | Marquette | Wisconsin | A | 59.1 ft | 60 ft | 2025-11-23 |
| 12 | Oneonta Lake | Marinette | Wisconsin | A | 24.6 ft | 24 ft | 2025-11-22 |
| 13 | Silver Creek Estuary Lake | Green Lake | Wisconsin | F | - | 236 ft | 2025-11-20 |
| 14 | County K Marsh Lake | Green Lake | Wisconsin | F | - | - | 2025-11-20 |
| 15 | Lake Monona | Dane | Wisconsin | C | 22.1 ft | - | 2025-11-20 |
| 16 | King Lake | Marinette | Wisconsin | A | - | 70 ft | 2025-11-20 |
| 17 | Cloud Lake | Forest | Wisconsin | A | - | 25 ft | 2025-11-20 |
| 18 | Bug Lake | Forest | Wisconsin | A | - | - | 2025-11-19 |
| 19 | Lake Wingra | Dane | Wisconsin | B | 13.1 ft | 14 ft | 2025-11-18 |
| 20 | Joanis Lake | Portage | Wisconsin | B | - | - | 2025-11-18 |
| 21 | Honey Lake | Walworth | Wisconsin | D | 8.2 ft | 6 ft | 2025-11-17 |
| 22 | Deep Lake | Washburn | Wisconsin | A | 22.1 ft | 25 ft | 2025-11-17 |
| 23 | Tuttle Lake | Marquette | Wisconsin | A | 37.9 ft | 33 ft | 2025-11-17 |
| 24 | Mercer Lake | Oneida | Wisconsin | A | 24.6 ft | 23 ft | 2025-11-16 |
| 25 | Lake of the Woods Barron Co. at | Barron | Wisconsin | B | 10.7 ft | 55 ft | 2025-11-15 |
| 26 | Wiley Lake | Bayfield | Wisconsin | B | - | - | 2025-11-15 |
| 27 | Fish Lake | Waushara | Wisconsin | A | - | 37 ft | 2025-11-15 |
| 28 | Cable Lake | Bayfield | Wisconsin | A | 50.9 ft | - | 2025-11-15 |
| 29 | Baker Lake | Vilas | Wisconsin | B | 14.4 ft | 21 ft | 2025-11-14 |
| 30 | Round Lake | Oneida | Wisconsin | B | 14.4 ft | 15 ft | 2025-11-13 |
| 31 | Lake Mendota | Dane | Wisconsin | B | 18 ft | 83 ft | 2025-11-13 |
| 32 | Island Lake | Oneida | Wisconsin | A | 23 ft | 26 ft | 2025-11-13 |
| 33 | Townline Lake | Oneida | Wisconsin | A | 19.7 ft | 19 ft | 2025-11-13 |
| 34 | Wood Lake | Marquette | Wisconsin | A | 45.9 ft | 53 ft | 2025-11-13 |
| 35 | Wolf Lake | Fond du Lac | Wisconsin | B | 18 ft | 47 ft | 2025-11-12 |
| 36 | Pewaukee Lake | Waukesha | Wisconsin | A | 18.9 ft | 45 ft | 2025-11-12 |
| 37 | Round Lake | Waushara | Wisconsin | A | 42.7 ft | - | 2025-11-11 |
| 38 | Golden Lake | Waukesha | Wisconsin | A | 42.7 ft | 44 ft | 2025-11-11 |
| 39 | Bear Lake | Oneida | Wisconsin | A | 27.7 ft | 20 ft | 2025-11-10 |
| 40 | Unnamed Lake | Waushara | Wisconsin | A | - | - | 2025-11-10 |
| 41 | Greater Bass Lake | Langlade | Wisconsin | A | - | 25 ft | 2025-11-10 |
| 42 | Ward Lake | Burnett | Wisconsin | A | - | 21 ft | 2025-11-09 |
| 43 | White River Pond | Waushara | Wisconsin | A | 31.6 ft | 29 ft | 2025-11-08 |
| 44 | Lake Waubesa | Dane | Wisconsin | B | 10.3 ft | 38 ft | 2025-11-07 |
| 45 | Lake Kegonsa | Dane | Wisconsin | B | 12.3 ft | 32 ft | 2025-11-07 |
| 46 | Long Lake | Waushara | Wisconsin | A | 45.9 ft | 71 ft | 2025-11-07 |
| 47 | Milwaukee Harbor South Half Lake | Milwaukee | Wisconsin | D | 7.4 ft | - | 2025-11-05 |
| 48 | Milwaukee Harbor Lake | Milwaukee | Wisconsin | D | 6.6 ft | - | 2025-11-05 |
| 49 | Milwaukee Harbor Lake | Milwaukee | Wisconsin | C | 6.6 ft | - | 2025-11-05 |
| 50 | Milwaukee River Lake | Milwaukee | Wisconsin | C | 4.9 ft | - | 2025-11-05 |
| 51 | Milwaukee Harbor Lake | Milwaukee | Wisconsin | C | 7.5 ft | - | 2025-11-05 |
| 52 | Milwaukee Harbor North Half Lake | Milwaukee | Wisconsin | C | 7.2 ft | - | 2025-11-05 |
| 53 | Milwaukee Harbor Lake | Milwaukee | Wisconsin | C | 8.2 ft | - | 2025-11-05 |
| 54 | Milwaukee Harbor Lake | Milwaukee | Wisconsin | C | 8.5 ft | - | 2025-11-05 |
| 55 | Milwaukee Harbor Lake | Milwaukee | Wisconsin | C | 8.2 ft | - | 2025-11-05 |
| 56 | Milwaukee Harbor Estuary Lake | Milwaukee | Wisconsin | D | 3.9 ft | - | 2025-11-04 |
| 57 | Spencer Lake | Waupaca | Wisconsin | A | 27.9 ft | 53 ft | 2025-11-04 |
| 58 | Kelly Lake | Oconto | Wisconsin | A | 34.5 ft | 41 ft | 2025-11-04 |
| 59 | Okauchee Lake | Waukesha | Wisconsin | A | 36.1 ft | 90 ft | 2025-11-04 |
| 60 | Archibald Lake | Oconto | Wisconsin | A | 55.4 ft | 50 ft | 2025-11-04 |
| 61 | Wheeler Lake | Oconto | Wisconsin | A | 72.2 ft | - | 2025-11-04 |
| 62 | Amy Bell Lake | Washington | Wisconsin | A | - | 37 ft | 2025-11-04 |
| 63 | Bullhead Lake | Manitowoc | Wisconsin | C | 13.1 ft | 40 ft | 2025-10-31 |
| 64 | Sandhill Lake | Ozaukee | Wisconsin | B | 24.6 ft | - | 2025-10-31 |
| 65 | Cruson Slough Lake | Richland | Wisconsin | A | 25.1 ft | - | 2025-10-31 |
| 66 | Rice Lake | Walworth | Wisconsin | C | 6.2 ft | 10 ft | 2025-10-30 |
| 67 | Tug Lake | Lincoln | Wisconsin | C | 6.6 ft | 21 ft | 2025-10-30 |
| 68 | Smith Lake | Washington | Wisconsin | B | 13.1 ft | - | 2025-10-30 |
| 69 | Lake Owen | Bayfield | Wisconsin | A | 78.7 ft | 95 ft | 2025-10-30 |
| 70 | Crystal Lake | Marquette | Wisconsin | A | 55.8 ft | 60 ft | 2025-10-30 |
| 71 | Clear Lake Sec. 24 T37n R7e | Oneida | Wisconsin | A | 31 ft | - | 2025-10-30 |
| 72 | Trout Bog Lake | Vilas | Wisconsin | A | - | 24 ft | 2025-10-30 |
| 73 | Little Rock Lake | Vilas | Wisconsin | A | - | - | 2025-10-30 |
| 74 | Crystal Bog Lake | Vilas | Wisconsin | A | - | 8 ft | 2025-10-30 |
| 75 | Big Eau Pleine Lake | Marathon | Wisconsin | F | 3.3 ft | - | 2025-10-29 |
| 76 | Helen Lake | Iowa | Wisconsin | B | 11.3 ft | 28 ft | 2025-10-29 |
| 77 | Bakkens Pond | Sauk | Wisconsin | B | 8.2 ft | - | 2025-10-29 |
| 78 | Hill Slough Lake | Sauk | Wisconsin | B | 14.4 ft | - | 2025-10-29 |
| 79 | Long Lake | Sauk | Wisconsin | B | 13.5 ft | - | 2025-10-29 |
| 80 | Spider Lake | Iron | Wisconsin | A | 27.9 ft | - | 2025-10-29 |
| 81 | Cochran Lake | Price | Wisconsin | A | 37.7 ft | 20 ft | 2025-10-29 |
| 82 | Breakfast Lake | Bayfield | Wisconsin | A | 41 ft | - | 2025-10-29 |
| 83 | Lake Lucerne | Forest | Wisconsin | A | 61.5 ft | 73 ft | 2025-10-29 |
| 84 | Franklin Lake | Oneida | Wisconsin | A | 53.3 ft | - | 2025-10-29 |
| 85 | Lake Mallalieu | St. Croix | Wisconsin | C | 9 ft | 17 ft | 2025-10-28 |
| 86 | Hidden Valley Lake | Lafayette | Wisconsin | B | 16.4 ft | 18 ft | 2025-10-28 |
| 87 | Great Bass Lake | Oneida | Wisconsin | A | 34.5 ft | 24 ft | 2025-10-28 |
| 88 | Tambling Lake | Vilas | Wisconsin | A | - | 11 ft | 2025-10-28 |
| 89 | Delavan Lake | Walworth | Wisconsin | B | 24.8 ft | 52 ft | 2025-10-27 |
| 90 | Nelson Lake | Sawyer | Wisconsin | A | 15.2 ft | - | 2025-10-27 |
| 91 | Armour Lake | Vilas | Wisconsin | A | 34.5 ft | 56 ft | 2025-10-27 |
| 92 | Round Lake | Burnett | Wisconsin | B | 16.4 ft | 27 ft | 2025-10-26 |
| 93 | Reisner Lake | Florence | Wisconsin | A | 21.3 ft | - | 2025-10-26 |
| 94 | Round Lake | Shawano | Wisconsin | A | 29.5 ft | 39 ft | 2025-10-24 |
| 95 | Pine Lake | Shawano | Wisconsin | A | 32.8 ft | 35 ft | 2025-10-24 |
| 96 | Pretty Lake | Waukesha | Wisconsin | A | 39.4 ft | 31 ft | 2025-10-24 |
| 97 | Wolf Lake | Adams | Wisconsin | A | 50.9 ft | 58 ft | 2025-10-24 |
| 98 | Grass Lake | Shawano | Wisconsin | A | 28.7 ft | 52 ft | 2025-10-24 |
| 99 | Waubeesee Lake | Racine | Wisconsin | A | 32 ft | 73 ft | 2025-10-24 |
| 100 | Elsie Lake | Vilas | Wisconsin | A | 42.7 ft | 22 ft | 2025-10-24 |
Source: EPA Water Quality Portal. Sample dates reflect when monitoring crews collected water samples — typically there is a multi-month lag before the data appears in the federal portal.