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LakeQuality

Agnes Lake vs Shell Lake

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

Agnes Lake has a higher water quality grade (B, Good) than Shell Lake (F, Very Poor). Both are in St. Louis County, Minnesota.

Both Agnes Lake and Shell 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. Agnes Lake (B) is materially cleaner than Shell Lake (F). 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 — Agnes 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?

B

Agnes Lake

St. Louis County, Minnesota

Good clarity, visible to about 13.5 ft.

F

Shell Lake

St. Louis County, Minnesota

Very murky, less than 3 ft of visibility.

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.

MetricAgnes LakeShell Lake
Overall GradeB (Good)F (Very Poor)
Water Clarity13.5 ft3 ft
PhosphorusNo dataNo data
Chlorophyll-a (Algae)No dataNo data
Maximum Depth30 ft15 ft
Surface Area1.0K acres493.3 acres
Public AccessNoNo
Fish Species11
Trophic Stateoligotrophiceutrophic

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

Verdict

Agnes Lake wins on overall water quality with a Grade B versus Shell Lake's Grade F. Water clarity: 13.5 ft vs 3 ft. For fishing diversity, Agnes Lake also leads with 1 species.