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LakeQuality

Long Lake vs St. Clair Lake

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

Long Lake has a higher water quality grade (A, Excellent) than St. Clair Lake (C, Fair). Both are in Becker County, Minnesota.

Both Long Lake and St. Clair 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. Long Lake (A) is materially cleaner than St. Clair Lake (C). A gap that wide is unlikely to close in a single year of remediation work; it reflects multi-decade differences in the lakes themselves.

For a recreational visitor, the wider grade gap is decisive — Long 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?

A

Long Lake

Becker County, Minnesota

Crystal clear, you can see 15.1 ft down.

C

St. Clair Lake

Becker County, Minnesota

Murky, only visible to about 4.6 ft.

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.

MetricLong LakeSt. Clair Lake
Overall GradeA (Excellent)C (Fair)
Water Clarity15.1 ft4.6 ft
PhosphorusNo data50 µg/L
Chlorophyll-a (Algae)No dataNo data
Maximum Depth--
Surface Area45 acres45 acres
Public AccessUnknownUnknown
Fish Species10
Trophic Stateoligotrophiceutrophic

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

Verdict

Long Lake wins on overall water quality with a Grade A versus St. Clair Lake's Grade C. Water clarity: 15.1 ft vs 4.6 ft. For fishing diversity, Long Lake also leads with 1 species.