Seeley Lake Middle Basin is a cold, clear oligotrophic lake in Missoula County, Montana. Water quality is graded A based on 2 sampling years through 2022. Compared to the 59 other monitored lakes in Missoula County, Seeley Lake Middle Basin ranks #5 for water quality.
Source: EPA Water Quality Portal sampling records, Montana DNR, last sampled 2022-09-20. Grade methodology: LakeGrade methodology.
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Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Crystal clear, you can see 15.4 ft down. Phosphorus level: 8.1 µg/L. Trophic State Index: 36.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 15.4 ft | A |
| Phosphorus | 8.1 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 36 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Seeley Lake Middle Basin
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Fishing Seeley Lake Middle Basin
Location
County Ranking
Ranked #5 of 60 lakes in Missoula County
Nearby Lakes in Missoula County
Explore Seeley Lake Middle Basin across LakeGrade
More Montana Lake Rankings
Other Grade A Lakes in Montana
Oligotrophic Lakes in Montana
More records, surveys & data sources
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2022-09-20
Monitoring stations: 1