Posey Lake
Garfield County, Utah11 acresView mapDirections
Utah DWQ publishes the water-quality measurements for Posey Lake. Here is what has been measured.
- Oligotrophic
- Public access
- Limited data
Posey Lake in Garfield County, Utah has water-quality measurements published by Utah DWQ, shown here as reported. Water clarity: 16.4 ft visibility. Phosphorus: 18.5 µg/L. Chlorophyll-a (algae): 1.2 µg/L. Surface area: 11 acres.
Posey Lake is a 11-acre cold, clear oligotrophic lake in Garfield County, Utah. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available. Compared to the 9 other monitored lakes in Garfield County, Posey Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, Utah DWQ, last sampled 2025-09-03. Methodology: how these readings are compared.
What Posey Lake is good for
From access and monitoring records, not editorial picks.
- Clear water16.4 ft of visibility
- Camping1 public campground nearby
Swimming conditions
Readings onlyLimited data
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Posey Lake is safe to swim in today is a call for the Utah Division of Water Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Posey Lake
These are the measurements Utah DWQ publishes for Posey Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Crystal clear, you can see 16.4 ft down. Phosphorus 18.5 µg/L. Chlorophyll-a 1.2 µg/L. TSI 39.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 16.4ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 18.5µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 1.2µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 39 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Posey Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
11 acres
Public access
Yes
Listed by Utah DWQ
No bathymetric survey has been published for Posey Lake, so its depth is not documented here.
Recreation & Access
Public campgrounds near Posey Lake
- Posey Lake Campground0.3 km
Nearest public campgrounds in the USGS National Map inventory, within about 3 miles. An empty list means USGS records no campground that close, which is not the same as camping being unavailable. Where the source gives an official reservation link, it is used; the cabin and hotel search does not cover campsites. More camping lakes
Stays via Stay22
Stays 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
Prices for Oct 30–Nov 1, 4 adults. Change dates on the map below.
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Fishing Posey Lake
Water quality readings over time
2 seasons of samples on record (2019–2025). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Stable2 years
Chlorophyll-a
Improving-0.58 µg/L/yr2 years
Reservoir Info (USACE NID)
Posey Lake is a man-made reservoir impounded by the Posy Lake, built primarily for recreation; earth-type dam, 15 ft tall and 120 ft long.
- Surface area
- 11 ac
- Normal storage
- 50 ac-ft
- Hazard class
- Low
- Owner
- USDA FS
All listed purposes: Recreation;Other.
Source: USACE National Inventory of Dams, NID ID UT00766 · Operator website
Nearby Lakes in Garfield County
Frequently asked questions about Posey Lake
Where is Posey Lake?
- Posey Lake is a lake in Garfield County, Utah. Its water-quality measurements are published by Utah DWQ and shown on this page as reported.
What is the water quality of Posey Lake?
- Posey Lake in Garfield County, Utah has water-quality measurements published by Utah DWQ, shown here as reported. Water clarity: 16.4 ft visibility. Phosphorus: 18.5 µg/L. Chlorophyll-a (algae): 1.2 µg/L. Surface area: 11 acres.
Is Posey Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Can I fish at Posey Lake?
- Public access to Posey Lake is listed as yes on the lake record. Seasons, size and bag limits, and whether you need a license are set by Utah's fish and wildlife agency, so check its current regulations before you go.
Are there campgrounds on Posey Lake?
- Posey Lake has 1 public campground from USGS The National Map within 5 km, including Posey Lake Campground. This is a location join, not a booking. Cabins and hotels are listed separately; campsite reservations use the official link when the source provides one.
Explore Posey Lake across LakeQuality
2 documented falls within 16.8 mi, nearest Upper Calf Creek Falls
Species activity outlook by water temperature and season
Where to stay at Utah's top lakes, each with its readings
Utah's cleanest lakes, ranked on agency measurements
Planning a trip around Capitol Reef?
Posey Lake is about 34 miles from Capitol Reef National Park. Crowds there swing hard by season, so the month you pick changes both how busy the park is and what lodging costs.
Best time to visit Capitol Reef →More lakes in Utah
Other Lakes in Utah
Oligotrophic Lakes in Utah
Where this data comes from
16 measurements from 1 monitoring station, 2019–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Utah Department Of Environmental Quality
UTAHDWQ_WQX16 samples · 2019–2025
Analytical methods
- Field Measurements
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Public campgrounds from USGS The National Map Structures, within about 3 miles