Granite Springs Reservoir
Laramie County, Wyoming190 acresView mapDirections
Clarity, phosphorus, and algae sit in the clean band for this region.
↓ down from A at the last regrade
- Oligotrophic
- #2 of 8 in the county
- 15 ft max depth
- Public access
- Limited data
Granite Springs Reservoir in Laramie County, Wyoming has a water quality grade of B (Good). Water clarity: 11.8 ft visibility. Phosphorus: 10 µg/L. Surface area: 190 acres.
- Clarity
- 11.8 ft
- Max depth
- ~15 ft est.
- Area
- 190 acres
- Type
- Oligotrophic
- Phosphorus
- 10 µg/L
- Trend
- ↑ Improving
- Public access
- Yes
Stays via Stay22
Stays near Granite Springs Reservoir
Compare lakeside cabins, hotels, and vacation rentals near Granite Springs Reservoir in Laramie 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 Granite Springs Reservoir
Prices for Sep 11–13, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a trip? Cabins and lodging at Granite Springs Reservoir → · more Wyoming lake trips
Watch Granite Springs Reservoir’s letter
Email me if this lake’s grade moves. Grades stay free.
Or email
Granite Springs Reservoir is a 190-acre cold, clear oligotrophic lake in Laramie County, Wyoming with an estimated average depth of about 15 feet. Water quality is graded B based on 1 sampling years through 2018. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available. Compared to the 7 other monitored lakes in Laramie County, Granite Springs Reservoir ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Wyoming DEQ, last sampled 2018-09-06. Grade methodology: LakeQuality methodology.
What Granite Springs Reservoir is good for
From access and monitoring records, not editorial picks.
- Clear water11.8 ft of visibility
Swimming Safety
Grade onlyLimited 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 B is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
Water Quality Grade: B (Good)
Good clarity, visible to about 11.8 ft. Phosphorus 10 µg/L. TSI 39. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 11.8 ft | Not graded |
| Phosphorus | 10 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 39 | Oligotrophic |
Low nutrients, clear water. The letter is not a swimming clearance.
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~15 ft est. |
| Average Depth | ~15 ft est. |
| Surface Area | 190 acres |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Wyoming has not published bathymetry for Granite Springs Reservoir.
Lake Size & Watershed
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.
Fishing Granite Springs Reservoir
Water Quality Trend: ↑ Improving
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.283 m/yr | 2 |
| Phosphorus | → Stable | 0 µg/L/yr | 2 |
Reservoir Info (USACE NID)
Granite Springs Reservoir is a man-made reservoir impounded by the Granite Springs (completed 1904), built primarily for water supply on the Middle Crow Creek; masonry-type dam, 90 ft tall and 423 ft long.
- Surface area
- 190 ac
- Normal storage
- 5,220 ac-ft
- Max storage
- 5,780 ac-ft
- Drainage area
- 28.4 sq mi
- Hazard class
- High
- Owner
- CITY OF CHEYENNE-CBPU
Source: USACE National Inventory of Dams, NID ID WY00001 · Operator website
County Ranking
Ranked #2 of 8 lakes in Laramie County
Nearby Lakes in Laramie County
Frequently asked questions about Granite Springs Reservoir
Where is Granite Springs Reservoir?
- Granite Springs Reservoir is a lake in Laramie County, Wyoming. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Granite Springs Reservoir?
- Granite Springs Reservoir in Laramie County, Wyoming has a water quality grade of B (Good). Water clarity: 11.8 ft visibility. Phosphorus: 10 µg/L. Surface area: 190 acres.
Is Granite Springs Reservoir safe to swim in?
- The B is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
How deep is Granite Springs Reservoir?
- No published bathymetric survey covers Granite Springs Reservoir, 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 190 acres.
Explore Granite Springs Reservoir across LakeQuality
Species activity outlook by water temperature and season
Where to stay at Wyoming's top lakes, each with its grade
Low nutrients, clear water. The letter is not a swimming clearance.
Wyoming's cleanest and most-polluted lakes, ranked
More Wyoming Lake Rankings
Other Grade B Lakes in Wyoming
Oligotrophic Lakes in Wyoming
Where this data comes from
12 measurements from 1 monitoring station, 2015–2018. 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_WATERSHED12 samples · 2015–2018
Analytical methods
- Secchi
- 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.
Other records on this page
Lake size & watershed from HydroLAKES (HydroSHEDS)