Gladwin County Lake Quality
Wisconsin, 9 lakes, average grade B (Good)
Only 9 lakes in Gladwin 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. The county-wide average lands at B — solid water quality with most lakes carrying clear summer transparency and low-to-moderate phosphorus.
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. Lake Lancer (A) is the cleanest in the county.
Quick Answers for Gladwin County
Planning a trip? Check special fishing regulations for Lake Lancer, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
All Lakes in Gladwin County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Lake Lancer | A | 15.5 ft | - | - |
| 2 | Island Lake Central Basin; Sherman Township | A | 16.5 ft | - | - |
| 3 | Lancer Lake Southeast | A | 13.2 ft | - | - |
| 4 | Lancelot Lake Southwest Basin | B | 10 ft | - | - |
| 5 | Grass Lake | B | 4 ft | - | - |
| 6 | Little Lake Twenty | C | 9 ft | - | - |
| 7 | Lake Twenty East Basin | C | 9 ft | - | - |
| 8 | Lake Lancelot | C | 9.3 ft | - | - |
| 9 | Grass Lake | D | 4 ft | - | - |
Source: EPA National Aquatic Resource Surveys, 2026.