Gunflint Lake vs Loon Lake
Water quality, depth, fish species, and recreation comparison.
Gunflint Lake and Loon Lake both received the same overall water quality grade of A (Excellent). Both are in Cook County, Minnesota.
Both Gunflint Lake and Loon Lake sit in Minnesota. 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 close: Gunflint Lake (A) and Loon Lake (A) 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.
Gunflint Lake
Crystal clear, you can see 16.5 ft down.
Loon Lake
Crystal clear, you can see 17.4 ft down.
Side-by-Side Metrics
| Metric | Gunflint Lake | Loon Lake |
|---|---|---|
| Overall Grade | A (Excellent) | A (Excellent) |
| Water Clarity | 16.5 ft | 17.4 ft |
| Phosphorus | 5.5 µg/L | 5 µg/L |
| Chlorophyll-a (Algae) | 2.6 µg/L | 1.6 µg/L |
| Maximum Depth | 200 ft | 202 ft |
| Surface Area | 4,009 acres | 1,095 acres |
| Public Access | Yes | Yes |
| Fish Species | 12 | 10 |
| Trophic State | oligotrophic | oligotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Both lakes earn the same Grade A. The tiebreakers come down to clarity (Gunflint Lake: 16.5 ft, Loon Lake: 17.4 ft) and what you want from the lake. Gunflint Lake supports more documented fish species.
Source: EPA National Aquatic Resource Surveys, 2026.