Lower Sunshine Reservoir
Park County, Wyoming1,049 acresView mapDirections
Wyoming DEQ publishes the water-quality measurements for Lower Sunshine Reservoir. Here is what has been measured.
- Mesotrophic
- 162 ft max depth
- Public access
- Limited data
Lower Sunshine Reservoir in Park County, Wyoming has water-quality measurements published by Wyoming DEQ, shown here as reported. Water clarity: 10.6 ft visibility. Phosphorus: 10 µg/L. Surface area: 1049 acres.
Lower Sunshine Reservoir is a 1,049-acre mesotrophic lake in Park County, Wyoming with an estimated average depth of about 162 feet. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 4 other monitored lakes in Park County, Lower Sunshine Reservoir ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Wyoming DEQ, last sampled 2021-07-20. Methodology: how these readings are compared.
Lower Sunshine Reservoir covers about 1,000 acres in Park County. It has one public boat landing. If you are planning to stay, you can search lake houses and cabins around Lower Sunshine Reservoir on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Lower Sunshine Reservoir is good for
From access and monitoring records, not editorial picks.
- Clear water10.6 ft of visibility
- Boat launch1 documented ramp
- Big water1,049 acres
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 Lower Sunshine Reservoir is safe to swim in today is a call for the Wyoming Department of Environmental Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Lower Sunshine Reservoir
These are the measurements Wyoming DEQ publishes for Lower Sunshine Reservoir, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 10.6 ft. Phosphorus 10 µg/L. TSI 40.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 10.6ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 10µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 40 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Lower Sunshine Reservoir
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
~162 ft est.
Surface area
1,049 acres
Public access
Yes
Listed by Wyoming DEQ
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Wyoming has not published bathymetry for Lower Sunshine Reservoir.
Lake Size & Watershed
Watershed (drainage) area
24 sq mi
HydroLAKES / HydroSHEDS
Shoreline
6 mi
HydroLAKES / HydroSHEDS
Elevation
6,253 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Recreation & Access
- Sunshine Reservoir, LowerPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Lower Sunshine Reservoir
Compare lakeside cabins, hotels, and vacation rentals near Lower Sunshine Reservoir in Park 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.
Top-rated places to stay near Lower Sunshine Reservoir
Prices for Oct 30–Nov 1, 4 adults. Change dates on the map below.
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Fishing Lower Sunshine Reservoir
Reservoir Info (USACE NID)
Lower Sunshine Reservoir is a man-made reservoir impounded by the Lower Sunshine (completed 1972), built primarily for irrigation on the Sunshine Creek Offstream; earth-type dam, 162 ft tall and 1,660 ft long.
- Surface area
- 1,049 ac
- Normal storage
- 58,748 ac-ft
- Max storage
- 71,800 ac-ft
- Drainage area
- 26.5 sq mi
- Hazard class
- High
- Owner
- GREYBULL VALLEY IRRIGATION DISTRICT
All listed purposes: Irrigation;Fire Protection, Stock, Or Small Fish Pond;Hydroelectric.
Source: USACE National Inventory of Dams, NID ID WY01096 · Operator website
Nearby Lakes in Park County
Frequently asked questions about Lower Sunshine Reservoir
Where is Lower Sunshine Reservoir?
- Lower Sunshine Reservoir is a lake in Park County, Wyoming. Its water-quality measurements are published by Wyoming DEQ and shown on this page as reported.
What is the water quality of Lower Sunshine Reservoir?
- Lower Sunshine Reservoir in Park County, Wyoming has water-quality measurements published by Wyoming DEQ, shown here as reported. Water clarity: 10.6 ft visibility. Phosphorus: 10 µg/L. Surface area: 1049 acres.
Is Lower Sunshine Reservoir safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Lower Sunshine Reservoir?
- No published bathymetric survey covers Lower Sunshine Reservoir, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 162 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 1049 acres.
Are there boat ramps on Lower Sunshine Reservoir?
- Lower Sunshine Reservoir has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Sunshine Reservoir, Lower. Public access is listed as yes.
Can I fish at Lower Sunshine Reservoir?
- Lower Sunshine Reservoir has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Wyoming's fish and wildlife agency, so check its current regulations before you go.
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Where this data comes from
8 measurements from 2 monitoring stations, 2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- State of Wyoming Department of Environmental Quality Watershed Program
WYDEQ_WATERSHED8 samples · 2021
Analytical methods
- Secchi
- Total Phosphorus After Block Digestion
Monitoring station identifiers (2)
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory