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LakeQuality

Oyster Lake vs Shell Lake

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

Oyster Lake has a higher water quality grade (C, Fair) than Shell Lake (F, Very Poor). Both are in St. Louis County, Minnesota.

Both Oyster 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. The grades are meaningfully apart: Oyster Lake grades a C while Shell Lake grades a F. That two-letter spread reflects real underlying differences — different watershed inputs, different depth profiles, or different monitoring rigor.

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

C

Oyster Lake

St. Louis County, Minnesota

Moderate clarity, visible to about 7.3 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.

MetricOyster LakeShell Lake
Overall GradeC (Fair)F (Very Poor)
Water Clarity7.3 ft3 ft
PhosphorusNo dataNo data
Chlorophyll-a (Algae)No dataNo data
Maximum Depth130 ft15 ft
Surface Area762.91 acres493.3 acres
Public AccessNoNo
Fish Species01
Trophic Statemesotrophiceutrophic

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

Verdict

Oyster Lake wins on overall water quality with a Grade C versus Shell Lake's Grade F. Water clarity: 7.3 ft vs 3 ft. For more fish-species variety, Shell Lake edges ahead with 1 documented species.