Keweenaw County Lake Quality
Michigan, 16 lakes, average grade B (Good)
There are 16 graded lakes in Keweenaw County. The mix is varied enough that the county-level average tells you the broad strokes, not the choose-this-cabin specifics. With an average grade of B, Keweenaw County sits comfortably above the Michigan median.
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 Lake Ahmik (B); the most-stressed is Chickenbone Lake (C).
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Quick Answers for Keweenaw County
Planning a trip? Check special fishing regulations for Lake Ahmik, whether the fish are safe to eat, and the best times to fish — or check the official Michigan fishing regulations.
Fishing in Keweenaw County
All Lakes in Keweenaw County
16 lakes · 11 graded, 5 not rated11 graded lakes · 5 not rated, hidden
| # | Lake | Grade | Clarity | Phosphorus | Algae | Trophic | Max Depth | Access |
|---|---|---|---|---|---|---|---|---|
| 1 | BLake AhmikKeweenaw | B | 6.6 ft | 15.2 µg/L | No recent samples | No recent samples | No recent samples | Not recorded |
| 2 | BGratiot LakeKeweenaw | B | 17 ft | 9 µg/L | No recent samples | No recent samples | 70 ft | Not recorded |
| 3 | BSargent LakeKeweenaw | B | 10.5 ft | 13.2 µg/L | No recent samples | No recent samples | No recent samples | Not recorded |
| 4 | BLake RichieKeweenaw | B | 9.2 ft | 16.1 µg/L | No recent samples | No recent samples | No recent samples | Not recorded |
| 5 | BLake HarveyKeweenaw | B | 10.4 ft | 12.2 µg/L | No recent samples | No recent samples | No recent samples | Not recorded |
| 6 | BBeaver LakeKeweenaw | B | 8.9 ft | 12.9 µg/L | No recent samples | No recent samples | No recent samples | Not recorded |
| 7 | BFeldtmann LakeKeweenaw | B | 7.5 ft | 11.5 µg/L | No recent samples | No recent samples | No recent samples | Not recorded |
| 8 | BLake DesorKeweenaw | B | 7.2 ft | 11.7 µg/L | No recent samples | No recent samples | No recent samples | Not recorded |
| 9 | BLake GeorgeKeweenaw | B | 8 ft | 9.9 µg/L | No recent samples | No recent samples | No recent samples | Not recorded |
| 10 | BSiskiwit LakeKeweenaw | B | 20.5 ft | 4.4 µg/L | No recent samples | No recent samples | No recent samples | Not recorded |
| 11 | CChickenbone LakeKeweenaw | C | 6.1 ft | 28.2 µg/L | No recent samples | No recent samples | No recent samples | Not recorded |
| NRLake GratiotKeweenaw | NR | 16.5 ft | No recent samples | No recent samples | No recent samples | 70 ft | ✓ Public | |
| NRWallace LakeKeweenaw | NR | No recent samples | No recent samples | No recent samples | No recent samples | No recent samples | Not recorded | |
| NRLake WhittleseyKeweenaw | NR | 11.6 ft | 23.3 µg/L | No recent samples | No recent samples | No recent samples | Not recorded | |
| NRHidden LakeKeweenaw | NR | 2.5 ft | 27.5 µg/L | No recent samples | No recent samples | No recent samples | Not recorded | |
| NREpidote LakeKeweenaw | NR | 7.2 ft | No recent samples | No recent samples | No recent samples | No recent samples | Not recorded |
NR = not rated: there is not enough recent sampling to support a letter. That is EPA Integrated Reporting Category 3 (insufficient information), not a failing grade. How grading works.
Lake Match
Which lake suits how you actually use one?
Six questions — swimming, fishing, quiet, cabins, drive time — and a shortlist of graded lakes that fit, with the water quality behind each one.
Other Counties in Michigan
See how Keweenaw County stacks up in the national county water-quality rankings, or browse the full directory of graded lakes across all 49 states and 2 Canadian provinces.
Source: EPA National Aquatic Resource Surveys, 2026.