Alger County Lake Quality
Wisconsin, 13 lakes, average grade B (Good)
Only 13 lakes in Alger 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.
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 Tie Lake (A); the most-stressed is Little Beaver Lake (D).
Quick Answers for Alger County
Planning a trip? Check special fishing regulations for Tie Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
All Lakes in Alger County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Tie Lake | A | 15 ft | - | - |
| 2 | Tie Lake; Deep Basin; Munising Township | A | 15 ft | - | - |
| 3 | Su04 Lake | A | 51.5 ft | - | - |
| 4 | Su08m Lake | A | 29.5 ft | - | - |
| 5 | Su05 Lake | A | - | - | - |
| 6 | Csmi 2021 Station Med Lake | A | - | - | - |
| 7 | Beaver Lake | A | 14.7 ft | - | 7.8 µg/L |
| 8 | Trapper'S Lake | B | 7.5 ft | - | 9.2 µg/L |
| 9 | Legion Lake | B | 9.3 ft | - | 17.8 µg/L |
| 10 | Grand Sable Lake | B | 8.9 ft | - | 11.8 µg/L |
| 11 | Chapel Lake | B | 7.9 ft | - | 23.5 µg/L |
| 12 | Miners Lake | B | 6.2 ft | - | 18.9 µg/L |
| 13 | Little Beaver Lake | D | 6.2 ft | - | - |
Source: EPA National Aquatic Resource Surveys, 2026.