McIlwain Lake
Roosevelt County, Montana81 acresView mapDirections
No nutrient or algae sampling on record from Montana DEQ for this lake.
McIlwain Lake in Roosevelt County, Montana has water-quality measurements published by Montana DEQ, shown here as reported. Surface area: 81 acres.
McIlwain Lake is a 81-acre lake in Roosevelt 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 McIlwain 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 McIlwain Lake
These are the measurements Montana DEQ publishes for McIlwain 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.
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Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
81 acres
Shoreline
2.8 mi
No bathymetric survey has been published for McIlwain Lake, so its depth is not documented here.
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Frequently asked questions about McIlwain Lake
Where is McIlwain Lake?
- McIlwain Lake is a lake in Roosevelt County, Montana. Its water-quality measurements are published by Montana DEQ and shown on this page as reported.
What is the water quality of McIlwain Lake?
- McIlwain Lake in Roosevelt County, Montana has water-quality measurements published by Montana DEQ, shown here as reported. Surface area: 81 acres.
Is McIlwain 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 McIlwain Lake come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.