Posey Lake is a cold, clear oligotrophic lake in Garfield County, Utah. Water quality is graded A based on 2 sampling years through 2025. Compared to the 12 other monitored lakes in Garfield County, Posey Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, Utah DNR, last sampled 2025-09-03. Grade methodology: LakeGrade methodology.
Watch Posey Lake 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
Crystal clear, you can see 16.4 ft down. Chlorophyll-a: 1.2 µg/L. Trophic State Index: 35.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 16.4 ft | A |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 1.2 µg/L | A |
| Trophic State Index (TSI) | 35 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Posey Lake
Compare lakeside cabins, hotels, and vacation rentals near Posey Lake in Garfield County, Utah — 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 Posey Lake
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 Posey Lake?
Get lake water-quality report cards plus the best cabin & lodging deals near Posey Lake — straight to your inbox. No spam, unsubscribe anytime.
Fishing Posey Lake
Location
County Ranking
Ranked #3 of 13 lakes in Garfield County
Nearby Lakes in Garfield County
Explore Posey Lake across LakeGrade
More Utah Lake Rankings
Other Grade A Lakes in Utah
Oligotrophic Lakes in Utah
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: 2025-09-03
Monitoring stations: 1