Sawmill Reservoir D
Sheridan County, Wyoming75 acresView mapDirections
Wyoming DEQ publishes the water-quality measurements for Sawmill Reservoir D. Here is what has been measured.
- Mesotrophic
- 15 ft max depth
- Limited data
Sawmill Reservoir D in Sheridan County, Wyoming has water-quality measurements published by Wyoming DEQ, shown here as reported. Phosphorus: 20 µg/L. Surface area: 75 acres.
Sawmill Reservoir D is a 75-acre mesotrophic lake in Sheridan County, Wyoming with an estimated average depth of about 15 feet. Compared to the 4 other monitored lakes in Sheridan County, Sawmill Reservoir D ranks #4 for water quality.
Source: EPA Water Quality Portal sampling records, Wyoming DEQ, last sampled 2017-09-12. Methodology: how these readings are compared.
Sawmill Reservoir D covers about 75 acres in Sheridan County. If you are planning to stay, you can search lake houses and cabins around Sawmill Reservoir D on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
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 Sawmill Reservoir D 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 Sawmill Reservoir D
These are the measurements Wyoming DEQ publishes for Sawmill Reservoir D, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data. Phosphorus 20 µg/L. TSI 47.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | No reading How deep a black-and-white disk stays visible from the surface. Higher is clearer. | |
| Total phosphorus | 20µg/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. | 47 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Sawmill Reservoir D
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
~15 ft est.
Surface area
75 acres
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Wyoming has not published bathymetry for Sawmill Reservoir D.
Lake Size & Watershed
Watershed (drainage) area
9 sq mi
HydroLAKES / HydroSHEDS
Shoreline
1.3 mi
HydroLAKES / HydroSHEDS
Elevation
8,212 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.
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Stays near Sawmill Reservoir D
Compare lakeside cabins, hotels, and vacation rentals near Sawmill Reservoir D in Sheridan 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.
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Reservoir Info (USACE NID)
Sawmill Reservoir D is a man-made reservoir impounded by the Sawmill (completed 1972), built primarily for irrigation on the Sawmill Creek; earth-type dam, 38 ft tall and 517 ft long.
- Surface area
- 75 ac
- Normal storage
- 1,275 ac-ft
- Max storage
- 1,831 ac-ft
- Drainage area
- 8.3 sq mi
- Hazard class
- High
- Owner
- SAWMILL RESERVOIR COMPANY (DON ROBERTS)
Source: USACE National Inventory of Dams, NID ID WY00677 · Operator website · Matched by proximity (0.15 km)
Nearby Lakes in Sheridan County
Frequently asked questions about Sawmill Reservoir D
Where is Sawmill Reservoir D?
- Sawmill Reservoir D is a lake in Sheridan County, Wyoming. Its water-quality measurements are published by Wyoming DEQ and shown on this page as reported.
What is the water quality of Sawmill Reservoir D?
- Sawmill Reservoir D in Sheridan County, Wyoming has water-quality measurements published by Wyoming DEQ, shown here as reported. Phosphorus: 20 µg/L. Surface area: 75 acres.
Is Sawmill Reservoir D safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Sawmill Reservoir D?
- No published bathymetric survey covers Sawmill Reservoir D, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 15 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 75 acres.
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Mesotrophic Lakes in Wyoming
Where this data comes from
3 measurements from 1 monitoring station, 2017. 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_WATERSHED3 samples · 2017
Analytical methods
- Total Phosphorus After Block Digestion
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
Lake size & watershed from HydroLAKES (HydroSHEDS)