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LakeQuality

Three Island Lake in Beltrami County, Minnesota has nutrient and algae measurements on record from state and federal monitoring. A water-quality reading is not a swimming clearance. The state water agency and county health departments post current advisories; check them before you swim.. Water clarity: 11.8 ft visibility. Phosphorus: 17 µg/L. Chlorophyll-a (algae): 4.1 µg/L. Always check local health department advisories before swimming.

Key Metrics

MetricValue
Water Clarity (Secchi Depth)11.8 ft
Phosphorus17 μg/L
Chlorophyll-a (Algae)4.1 μg/L
Maximum Depth25 ft
LocationBeltrami County, Minnesota

How does Three Island Lake compare?

With an overall water-quality readings of , Three Island Lake matches or beats the Minnesota state average. It ranks #29 of 85 lakes in Beltrami County by water quality score.

Water clarity (Secchi depth) sits at 11.8 feet. That counts as exceptional clarity — sunlight penetrates deep, supporting submerged plants and limiting algae. Algae levels (chlorophyll-a) measure 4.1 µg/L — low and well within safe swimming guidelines.