Marquette County Lake Quality
Wisconsin, 10 lakes, average grade B (Good)
Marquette County has 10 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, Marquette County sits comfortably above the Michigan median.
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. Shag Lake (A) is the cleanest in the county.
Quick Answers for Marquette County
Planning a trip? Check special fishing regulations for Shag Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
All Lakes in Marquette County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Shag Lake | A | 15.3 ft | - | - |
| 2 | Su21b Lake | A | - | - | - |
| 3 | Csmi 2016 Station Seq Lake | A | - | - | - |
| 4 | Lake Independence Central Basin; Powell Township Section 15 | B | 9 ft | - | - |
| 5 | Bass Lake North Basin; Forsyth Township | B | 12.5 ft | - | - |
| 6 | Shag Lake Northeast Basin | B | 14.3 ft | - | - |
| 7 | Bass Lake | B | 12 ft | - | - |
| 8 | Island Lake; Republic Township | B | 12 ft | - | - |
| 9 | Bass Lake Central Basin; Forsyth Township | B | 11.8 ft | - | - |
| 10 | Lake Independence | C | 9 ft | - | - |
Source: EPA National Aquatic Resource Surveys, 2026.