Lac Courte Oreilles Lake vs Moose Lake
Water quality, depth, fish species, and recreation comparison.
Lac Courte Oreilles Lake has a higher water quality grade (A, Excellent) than Moose Lake (C, Fair). Both are in Sawyer County, Wisconsin.
Both Lac Courte Oreilles Lake and Moose Lake sit in Wisconsin. A same-state comparison strips out the state-level water-quality regime as a variable: any grade differences here are about the lakes themselves, not the agencies grading them. The grades are meaningfully apart: Lac Courte Oreilles Lake grades a A while Moose Lake grades a C. That two-letter spread reflects real underlying differences — different watershed inputs, different depth profiles, or different monitoring rigor.
For a recreational visitor, the wider grade gap is decisive — Lac Courte Oreilles Lake is the better water-quality choice. For a researcher, the gap is the interesting part: what is different about the two watersheds, and which of those differences is mutable?
Lac Courte Oreilles Lake
Good clarity, visible to about 12.2 ft.
Moose Lake
Very murky, less than 2 ft of visibility.
Side-by-Side Metrics
| Metric | Lac Courte Oreilles Lake | Moose Lake |
|---|---|---|
| Overall Grade | A (Excellent) | C (Fair) |
| Water Clarity | 12.2 ft | 2 ft |
| Phosphorus | 15 µg/L | 28.9 µg/L |
| Chlorophyll-a (Algae) | 1.7 µg/L | No data |
| Maximum Depth | 90 ft | 21 ft |
| Surface Area | 5,139 acres | 1,559 acres |
| Public Access | Yes | Yes |
| Fish Species | 6 | 5 |
| Trophic State | mesotrophic | eutrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Lac Courte Oreilles Lake wins on overall water quality with a Grade A versus Moose Lake's Grade C. Water clarity: 12.2 ft vs 2 ft. For fishing diversity, Lac Courte Oreilles Lake also leads with 6 species.
Source: EPA National Aquatic Resource Surveys, 2026.