Pierre Lake Fishing

Temperature, dissolved oxygen, clarity, nutrients, chlorophyll-a, pH, and conductivity are observations from public monitoring records and may be historical. Thermocline depth is shown only when FishyNW can derive a strong vertical temperature gradient from a measured profile. It is not treated as a permanent lake characteristic.

Trophic indication uses the Carlson Trophic State Index only when FishyNW can normalize a measured chlorophyll-a, Secchi, or total-phosphorus value. It is a derived ecological indicator, not an agency impairment determination.

Seasonal Fish Habitat is shown only when verified bathymetry overlaps a same-day, same-station temperature and dissolved-oxygen profile. It is a historical screening snapshot, not a live prediction of where fish are located.

For lake trout, FishyNW uses the broader USGS-tested screening combination of water at or below 15°C (59°F) and dissolved oxygen at or above 4 mg/L. For other coldwater species, FishyNW does not invent a preferred-temperature threshold; it shows only the observed thermocline-to-oxygenated-depth refuge when the evidence supports it.

Harmful-algae status is never inferred from missing data. Always check the linked state source for current advisories before contact recreation.