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Birch Lake reads lower on nutrients and algae than Lake Winnibigoshish. Both are in Cass County, Minnesota.

Reviewed by LakeQuality Editorial Team · Updated

Birch Lake and Lake Winnibigoshish 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. Birch Lake reads materially cleaner than Lake Winnibigoshish on nutrients and algae. 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 gap in the readings is decisive: Birch Lake has the lower nutrient and algae numbers. For a researcher, the gap is the interesting part: what is different about the two watersheds, and which of those differences is mutable?

Birch Lake

Cass County, Minnesota

Good clarity, visible to about 14 ft.

Lake Winnibigoshish

Cass County, Minnesota

Good clarity, visible to about 12.1 ft.

Side-by-Side Metrics

MetricBirch LakeLake Winnibigoshish
Water Clarity14 ft Better12.1 ft
Phosphorus12 µg/L Better29 µg/L
Chlorophyll-a (Algae)4 µg/L Better5.2 µg/L
Maximum Depth45 ft69.8 ft Better
Surface Area1,267 acres56,471 acres
Public AccessYesYes
Fish Species1420 Better
Trophic Statemesotrophicmesotrophic

A green ✓ marks the better value for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better). Surface area and trophic state carry no tick — a bigger lake is not a better lake.

Verdict

Birch Lake reads lower on nutrients and algae than Lake Winnibigoshish. Water clarity: 14 ft vs 12.1 ft. For more fish-species variety, Lake Winnibigoshish edges ahead with 20 documented species.

Source: EPA National Aquatic Resource Surveys, 2026.