Island Lake vs Manitowish Lake
Water quality, depth, fish species, and recreation comparison.
Island Lake and Manitowish Lake both received the same overall water quality grade of B (Good). Both are in Vilas County, Wisconsin.
Island Lake and Manitowish Lake are both in Wisconsin — a same-state head-to-head where the comparison comes down to lake-specific differences in depth, watershed, and monitoring history rather than the broader state-level water-quality regime. The grades are close: Island Lake (B) and Manitowish Lake (B) are within one letter of each other on the LakeGrade rubric. The per-parameter sub-grades below will show where the small differences actually live.
With grades this close, the choice between the two lakes turns on non-water-quality factors: depth, fish species, public access, distance from home. The per-lake pages below cover all of those.
Island Lake
Good clarity, visible to about 9.9 ft.
Manitowish Lake
Good clarity, visible to about 12.5 ft.
Side-by-Side Metrics
| Metric | Island Lake | Manitowish Lake |
|---|---|---|
| Overall Grade | B (Good) | B (Good) |
| Water Clarity | 9.9 ft | 12.5 ft |
| Phosphorus | No data | No data |
| Chlorophyll-a (Algae) | No data | No data |
| Maximum Depth | 35 ft | 61 ft |
| Surface Area | 865 acres | 496 acres |
| Public Access | Unknown | Unknown |
| Fish Species | 0 | 0 |
| Trophic State | mesotrophic | mesotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Both lakes earn the same Grade B. The tiebreakers come down to clarity (Island Lake: 9.9 ft, Manitowish Lake: 12.5 ft) and what you want from the lake. Island Lake matches its peer on species count.