Dark Canyon Lake
San Juan County, UtahView mapDirections
Utah DWQ publishes the water-quality measurements for Dark Canyon Lake. Here is what has been measured.
- Mesotrophic
- Limited data
Dark Canyon Lake in San Juan County, Utah has water-quality measurements published by Utah DWQ, shown here as reported. Water clarity: 7.2 ft visibility. Phosphorus: 24.2 µg/L. Chlorophyll-a (algae): 3.2 µg/L.
Dark Canyon Lake is a mesotrophic lake in San Juan County, Utah. Overall water quality is improving over recent sampling years. Compared to the 9 other monitored lakes in San Juan County, Dark Canyon Lake ranks #8 for water quality.
Source: EPA Water Quality Portal sampling records, Utah DWQ, last sampled 2025-08-27. Methodology: how these readings are compared.
What Dark Canyon Lake is good for
From access and monitoring records, not editorial picks.
- Camping2 public campgrounds 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 Dark Canyon 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 Dark Canyon Lake
These are the measurements Utah DWQ publishes for Dark Canyon Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Moderate clarity, visible to about 7.2 ft. Phosphorus 24.2 µg/L. Chlorophyll-a 3.2 µg/L. TSI 47.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 7.2ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 24.2µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 3.2µg/L | Fair GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 47 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Dark Canyon Lake
Answers come straight from the public measurements and survey records on this page.
Recreation & Access
Public campgrounds near Dark Canyon Lake
- Upper Onion Creek Campground2.7 km
- Dewey Bridge Campground3.4 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 Dark Canyon Lake
Compare lakeside cabins, hotels, and vacation rentals near Dark Canyon Lake in San Juan 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 Dark Canyon Lake
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Follow Dark Canyon Lake’s readings
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Fishing Dark Canyon 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
Improving2 years
Chlorophyll-a
Improving-0.62 µg/L/yr2 years
Nearby Lakes in San Juan County
Frequently asked questions about Dark Canyon Lake
Where is Dark Canyon Lake?
- Dark Canyon Lake is a lake in San Juan County, Utah. Its water-quality measurements are published by Utah DWQ and shown on this page as reported.
What is the water quality of Dark Canyon Lake?
- Dark Canyon Lake in San Juan County, Utah has water-quality measurements published by Utah DWQ, shown here as reported. Water clarity: 7.2 ft visibility. Phosphorus: 24.2 µg/L. Chlorophyll-a (algae): 3.2 µg/L.
Is Dark Canyon Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Are there campgrounds on Dark Canyon Lake?
- Dark Canyon Lake has 2 public campgrounds from USGS The National Map within 5 km, including Upper Onion Creek Campground, Dewey Bridge 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 Dark Canyon Lake across LakeQuality
Planning a trip around Arches?
Dark Canyon Lake is about 28 miles from Arches 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 Arches →More lakes in Utah
Other Lakes in Utah
Mesotrophic Lakes in Utah
Where this data comes from
18 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_WQX18 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