Seeley Lake South Basin is a mesotrophic lake in Missoula County, Montana. Water quality is graded A based on 2 sampling years through 2021. Compared to the 59 other monitored lakes in Missoula County, Seeley Lake South Basin ranks #56 for water quality.
Source: EPA Water Quality Portal sampling records, Montana DNR, last sampled 2021-07-19. Grade methodology: LakeGrade methodology.
Watch Seeley Lake South Basin water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Good clarity, visible to about 14.4 ft. Phosphorus level: 17.4 µg/L. Trophic State Index: 42.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 14.4 ft | B |
| Phosphorus | 17.4 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 42 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Seeley Lake South Basin
Compare lakeside cabins, hotels, and vacation rentals near Seeley Lake South Basin in Missoula County, Montana — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Seeley Lake South Basin
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a trip to Seeley Lake South Basin?
Get lake water-quality report cards plus the best cabin & lodging deals near Seeley Lake South Basin — straight to your inbox. No spam, unsubscribe anytime.
Fishing Seeley Lake South Basin
Location
County Ranking
Ranked #56 of 60 lakes in Missoula County
Nearby Lakes in Missoula County
Explore Seeley Lake South Basin across LakeGrade
More Montana Lake Rankings
Other Grade A Lakes in Montana
Mesotrophic 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: 2021-07-19
Monitoring stations: 1