Thornton Lake
Granite County, Montana29 acresView mapDirections
No nutrient or algae sampling on record from Montana DEQ for this lake.
Thornton Lake in Granite County, Montana has water-quality measurements published by Montana DEQ, shown here as reported. Surface area: 29 acres.
Thornton Lake is a 29-acre lake in Granite 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 Thornton 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 Thornton Lake
These are the measurements Montana DEQ publishes for Thornton 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 Thornton Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
29 acres
Shoreline
1 mi
No bathymetric survey has been published for Thornton Lake, so its depth is not documented here.
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Stays near Thornton Lake
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Frequently asked questions about Thornton Lake
Where is Thornton Lake?
- Thornton Lake is a lake in Granite County, Montana. Its water-quality measurements are published by Montana DEQ and shown on this page as reported.
What is the water quality of Thornton Lake?
- Thornton Lake in Granite County, Montana has water-quality measurements published by Montana DEQ, shown here as reported. Surface area: 29 acres.
Is Thornton 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 Thornton Lake come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.