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LakeQuality

Yellowtail Reservoir Rpd

Big Horn County, WyomingView mapDirections

D
Nutrient-rich

Nutrients and algae run above the regional average.

↑ up from F at the last regrade

Water temp
No reading
No gauge
Clarity
No reading
No sample
Level
No reading
No gauge
Trend
Stable
4 years of samples
  • Eutrophic
  • #5 of 5 in the county
  • Limited data

Yellowtail Reservoir Rpd in Big Horn County, Wyoming has a water quality grade of D (Nutrient-rich). Phosphorus: 95 µg/L.

Type
Eutrophic
Phosphorus
95 µg/L
Trend
Stable
Loading map…

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Stays near Yellowtail Reservoir Rpd

Compare lakeside cabins, hotels, and vacation rentals near Yellowtail Reservoir Rpd in Big Horn County, Wyoming — 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Yellowtail Reservoir Rpd are listed below.

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Yellowtail Reservoir Rpd is a productive, nutrient-rich eutrophic lake in Big Horn County, Wyoming. Water quality is graded D based on 1 sampling years through 2016. Compared to the 4 other monitored lakes in Big Horn County, Yellowtail Reservoir Rpd ranks #5 for water quality.

Source: EPA Water Quality Portal sampling records, Wyoming DEQ, last sampled 2016-09-19. Grade methodology: LakeQuality methodology.

Swimming Safety

Grade only

Limited data

Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.

The D is nutrients and algae, not a swimming clearance. Check local advisories before you swim.

Get alerts for Yellowtail Reservoir Rpd

Water Quality Grade: D (Nutrient-rich)

No clarity data. Phosphorus 95 µg/L. TSI 70. The letter is not a swimming clearance.

MetricValueGrade
Water Clarity (Secchi Depth)No recent samples
Phosphorus95 µg/LPoor
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)70Eutrophic

High nutrients, frequent algae, reduced clarity

Fishing Yellowtail Reservoir Rpd

Based on 4 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Phosphorus Stable-0.11 µg/L/yr4
See year-by-year chart →

County Ranking

Ranked #5 of 5 lakes in Big Horn County

Nearby Lakes in Big Horn County

Frequently asked questions about Yellowtail Reservoir Rpd

Where is Yellowtail Reservoir Rpd?

Yellowtail Reservoir Rpd is a lake in Big Horn County, Wyoming. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.

What is the water quality grade for Yellowtail Reservoir Rpd?

Yellowtail Reservoir Rpd in Big Horn County, Wyoming has a water quality grade of D (Nutrient-rich). Phosphorus: 95 µg/L.

Is Yellowtail Reservoir Rpd safe to swim in?

The D is nutrients and algae, not a swimming clearance. Check local advisories before you swim.

Where this data comes from

10 measurements from 1 monitoring station, 2014–2016. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • State of Wyoming Department of Environmental Quality Watershed ProgramWYDEQ_WATERSHED10 samples · 2014–2016

Analytical methods

  • Total Phosphorus After Block Digestion
Monitoring station identifiers (1)

Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.