Big Sag Lake
Chouteau County, Montana149 acresView mapDirections
No nutrient or algae sampling on record from Montana DEQ for this lake.
Big Sag Lake in Chouteau County, Montana has water-quality measurements published by Montana DEQ, shown here as reported. Surface area: 149 acres.
Big Sag Lake is a 149-acre lake in Chouteau County, Montana.
Source: EPA Water Quality Portal sampling records, Montana DEQ. Methodology: how these readings are compared.
Swimming conditions
No readingNot rated
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Big Sag Lake is safe to swim in today is a call for the Montana Department of Environmental Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Big Sag Lake
These are the measurements Montana DEQ publishes for Big Sag Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data. TSI undefined.
Ask about Big Sag Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
149 acres
No bathymetric survey has been published for Big Sag Lake, so its depth is not documented here.
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Frequently asked questions about Big Sag Lake
Where is Big Sag Lake?
- Big Sag Lake is a lake in Chouteau County, Montana. Its water-quality measurements are published by Montana DEQ and shown on this page as reported.
What is the water quality of Big Sag Lake?
- Big Sag Lake in Chouteau County, Montana has water-quality measurements published by Montana DEQ, shown here as reported. Surface area: 149 acres.
Is Big Sag Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
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Where this data comes from
Measurements for Big Sag Lake come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.