Oscoda County Lake Quality
Wisconsin, 3 lakes, average grade A (Excellent)
Only 3 lakes in Oscoda County carry an active grade. The county-level summary is therefore representative of those specific lakes, not necessarily of every water body in the county. On average, Oscoda County lakes grade an A. That puts it near the top of the Michigan county ranking.
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 Mack Lake; Mentor Township; Section 9 (A); the most-stressed is Loon Lake (B).
Quick Answers for Oscoda County
Planning a trip? Check special fishing regulations for Mack Lake; Mentor Township; Section 9, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
All Lakes in Oscoda County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Mack Lake; Mentor Township; Section 9 | A | - | - | - |
| 2 | Loon Lake East Basin; T25north R2e | A | 14.5 ft | - | - |
| 3 | Loon Lake | B | 14.5 ft | - | - |
Source: EPA National Aquatic Resource Surveys, 2026.