Lafayette County Lake Quality
Wisconsin, 3 lakes, average grade B (Good)
Lafayette County has 3 graded lakes — a thin enough sample that one or two stressed lakes can move the county average noticeably. Use the per-lake pages below for what actually matters. With an average grade of B, Lafayette County sits comfortably above the Wisconsin median.
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 Hidden Valley Lake 1 (A); the most-stressed is Yellowstone Lake (D).
Quick Answers for Lafayette County
Planning a trip? Check special fishing regulations for Hidden Valley Lake 1, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
DNR Reports (4)
Wisconsin DNR Fisheries Survey resources for lakes in Lafayette County. browse all reports →
- 2023Yellowstone Lake rough fish removal assessment, 2023Fisheries Survey · WI DNR · 2023 (PDF)
- 2018Yellowstone Lake comprehensive survey 2018Comprehensive Survey · WI DNR · 2018 (PDF)
- 2016East Branch Pecatonica River catfish hoop net survey, 2016Fisheries Survey · WI DNR · 2016 (PDF)
- 2010Yellowstone Lake muskellunge 2010Musky Survey · WI DNR · 2010 (PDF)
All Lakes in Lafayette County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Hidden Valley Lake 1 | A | 20.5 ft | - | - |
| 2 | Hidden Valley Lake | B | 16.4 ft | 18 ft | 44.7 µg/L |
| 3 | Yellowstone Lake | D | 4.1 ft | 14 ft | 156 µg/L |
Source: EPA National Aquatic Resource Surveys, 2026.