Vernon County Lake Quality
Wisconsin, 1 lakes, average grade A (Excellent)
Vernon County has 1 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. On average, Vernon County lakes grade an A. That puts it near the top of the Wisconsin county ranking.
Most of the county's monitored lakes are shallow — under 50 feet — which means wind keeps the water column mixed all summer and sediment-bound phosphorus releases back into the surface layer whenever the bottom is disturbed. Sidie Hollow Lake (A) is the cleanest in the county.
Quick Answers for Vernon County
Planning a trip? Check special fishing regulations for Sidie Hollow 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 Vernon County. browse all reports →
- 2025Lower Reno Bottoms Mississippi River fall survey, 2025Fisheries Survey · WI DNR · 2025 (PDF)
- 2024Sidie Hollow Lake fishery survey, 2024Fisheries Survey · WI DNR · 2024 (PDF)
All Lakes in Vernon County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Sidie Hollow Lake | A | 29.5 ft | 22 ft | - |
Source: EPA National Aquatic Resource Surveys, 2026.