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LakeQuality

Alton Lake vs Clearwater Lake

Water quality, depth, fish species, and recreation comparison.

Clearwater Lake has a higher water quality grade (A, Excellent) than Alton Lake (B, Good). Both are in Cook County, Minnesota.

Alton Lake and Clearwater Lake are both in Minnesota — 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: Alton Lake (B) and Clearwater 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.

B

Alton Lake

Cook County, Minnesota

Good clarity, visible to about 13.5 ft.

A

Clearwater Lake

Cook County, Minnesota

Crystal clear, you can see 30 ft down.

Side-by-Side Metrics

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

MetricAlton LakeClearwater Lake
Overall GradeB (Good)A (Excellent)
Water Clarity13.5 ft30 ft
PhosphorusNo data4 µg/L
Chlorophyll-a (Algae)No dataNo data
Maximum Depth72 ft65 ft
Surface Area968.63 acres461.73 acres
Public AccessNoNo
Fish Species10
Trophic Stateoligotrophicoligotrophic

Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).

Verdict

Clearwater Lake wins on overall water quality with a Grade A versus Alton Lake's Grade B. Water clarity: 30 ft vs 13.5 ft. For more fish-species variety, Alton Lake edges ahead with 1 documented species.