Washburn County Lake Quality
Wisconsin, 48 lakes, average grade A (Excellent)
Washburn County's 48 graded lakes fall in the moderate-density bracket for Wisconsin. The county-level average smooths over real differences — a single agricultural watershed near the southwest corner can pull the average down even if the rest of the county runs clean. The county's average grade is A — among the cleanest in Wisconsin. 43 lakes pull an A on their own, and almost none fall into the D or F brackets.
The county's lakes lean shallow, which makes the grades sensitive to wind, sediment-resuspension, and any nutrient inputs from the watershed. The cleanest lake on the books is Long Lake (A); the most-stressed is Mud Lake (D).
Quick Answers for Washburn County
Planning a trip? Check special fishing regulations for Long Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
DNR Reports (2)
Wisconsin DNR Fisheries Survey resources for lakes in Washburn County. browse all reports →
- 2023Minong Flowage comprehensive survey, 2023Comprehensive Survey · WI DNR · 2023 (PDF)
- 2023Stone Lake comprehensive survey, 2023Comprehensive Survey · WI DNR · 2023 (PDF)
All Lakes in Washburn County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Long Lake | A | 29.5 ft | - | 17.5 µg/L |
| 2 | Spring Lake | A | - | 24 ft | 14.8 µg/L |
| 3 | Spider Lake | A | 30 ft | - | - |
| 4 | Silver Lake | A | 39.4 ft | 28 ft | - |
| 5 | Balsam Lake | A | 31.2 ft | - | 19.3 µg/L |
| 6 | Bass Lake | A | 52.5 ft | 31 ft | 12.3 µg/L |
| 7 | Bass Lake | A | 50.9 ft | 35 ft | - |
| 8 | Horseshoe Lake | A | 42.7 ft | - | 12.6 µg/L |
| 9 | Island Lake | A | 47.6 ft | 44 ft | - |
| 10 | Loon Lake | A | - | 63 ft | 7 µg/L |
| 11 | Little Sand Lake | A | 45.9 ft | - | - |
| 12 | Stone Lake | A | 75.5 ft | 49 ft | 10.8 µg/L |
| 13 | Big Mckenzie Lake | A | 33.6 ft | 71 ft | 17 µg/L |
| 14 | Tozer Lake | A | 50.9 ft | 53 ft | 13.2 µg/L |
| 15 | North Twin Lake | A | 29.5 ft | - | 13.7 µg/L |
| 16 | Middle Twin Lake at | A | 23 ft | - | - |
| 17 | Matthews Lake | A | 44.3 ft | 26 ft | 13.7 µg/L |
| 18 | Lower Mckenzie Lake | A | 36.1 ft | - | 18.8 µg/L |
| 19 | Deep Lake | A | 22.1 ft | 25 ft | 16.5 µg/L |
| 20 | Shell Lake | A | 50.9 ft | 36 ft | 15.2 µg/L |
| 21 | South Twin Lake | A | 46.8 ft | 29 ft | 11 µg/L |
| 22 | Slim Lake | A | 39.4 ft | - | 13.6 µg/L |
| 23 | Big Bass Lake | A | - | 27 ft | 11.7 µg/L |
| 24 | Lake Nancy | A | 47.6 ft | 39 ft | 13.5 µg/L |
| 25 | Mclain Lake | A | 31.2 ft | 30 ft | 14.2 µg/L |
| 26 | Ripley Lake | A | 27.9 ft | 27 ft | - |
| 27 | Un Lake | A | 30.8 ft | 17 ft | - |
| 28 | Middle Kimball Lake | A | 52.5 ft | 77 ft | 13.1 µg/L |
| 29 | Gilmore Lake | A | 32.8 ft | 36 ft | 16.3 µg/L |
| 30 | Little Ripley Lake | A | 19.7 ft | 14 ft | - |
| 31 | Bean Lake | A | 32.8 ft | 35 ft | 16.2 µg/L |
| 32 | Dunn Lake | A | 45.1 ft | 39 ft | - |
| 33 | Big Bass Lake | A | 17.9 ft | 27 ft | - |
| 34 | Unnamed Lake | A | 21.3 ft | - | - |
| 35 | No Mans Lake | A | 29.5 ft | 23 ft | - |
| 36 | Lower Kimball Lake | A | 19.7 ft | - | 18.5 µg/L |
| 37 | Gull Lake | A | 27.9 ft | 19 ft | - |
| 38 | Trego Lake | A | - | 36 ft | 16.5 µg/L |
| 39 | Birch Lake | A | 18 ft | 73 ft | 27.6 µg/L |
| 40 | Upper Kimball Lake | A | 32 ft | - | 20.4 µg/L |
| 41 | Spooner Lake | A | 26.2 ft | - | 22.7 µg/L |
| 42 | Kekegama Lake | A | 17.2 ft | 24 ft | 26.4 µg/L |
| 43 | Yellow River Flowage Lake | A | 32.8 ft | 17 ft | 23.1 µg/L |
| 44 | Potato Lake | B | 32.4 ft | 20 ft | 33.2 µg/L |
| 45 | Unnamed Lake | B | 10.8 ft | - | - |
| 46 | Unnamed Lake | B | - | - | 28.4 µg/L |
| 47 | Minong Flowage Lake | B | 12.3 ft | 21 ft | 37.2 µg/L |
| 48 | Mud Lake | D | - | 13 ft | 70.7 µg/L |
Source: EPA National Aquatic Resource Surveys, 2026.