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LakeQuality

Long Lake vs Thunder Lake

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

Long Lake and Thunder Lake both received the same overall water quality grade of A (Excellent). Both are in Cass County, Minnesota.

A

Long Lake

Cass County, Minnesota

Crystal clear, you can see 21.8 ft down.

A

Thunder Lake

Cass County, Minnesota

Crystal clear, you can see 16.4 ft down.

Side-by-Side Metrics

MetricLong LakeThunder Lake
Overall GradeA (Excellent)A (Excellent)
Water Clarity21.8 ft16.4 ft
Phosphorus9 µg/L10 µg/L
Chlorophyll-a (Algae)No dataNo data
Maximum Depth115 ft95 ft
Surface Area1.0K acres1.3K acres
Public AccessYesYes
Fish Species1417
Trophic Stateoligotrophicoligotrophic

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

Verdict

Both lakes earn the same Grade A. The tiebreakers come down to clarity (Long Lake: 21.8 ft, Thunder Lake: 16.4 ft) and what you want from the lake. Long Lake has fewer fish species than Thunder Lake.