Reservoir · Wyoming · United States · BOR RISE
Gray Reef Reservoir
Gray Reef Reservoir and Dam
79.4% full
Capacity
2.23 hm³
Volume stored
2 hm³
Vs month average
101% of normal
Coordinates
42.566°N, 106.699°W
Last updated
2026-10-27
Current fill
79.4%vs 7 days ago
-1.3 pplosing
vs 1 year ago
-9.8 ppyear-over-year
7-day trend
↓falling
Drought context
Storage vs October average
101%of normal
79.4% full on 2026-10-27, against an average of 78.9% for October across 6 years of readings (+0.5 points).
Drought Monitor at this site · 27 October 2026
D2severe drought
The ground at Gray Reef Reservoir's coordinates falls inside the D2 area of the weekly U.S. Drought Monitor map. That describes local conditions — rainfall, soil moisture, streamflow — not the reservoir's storage. Wyoming drought figures →
Data source: BOR RISE — US Bureau of Reclamation — daily reservoir storage volume. Capacity is the design (normal full-pool) capacity from the US National Inventory of Dams (NID); fill % = current volume ÷ design capacity. Last reading: 2026-10-27.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 42.566°N, 106.699°W · Open in Google Maps
About Gray Reef Reservoir
As of October 27, 2026, Gray Reef Reservoir is filled to 79.4% of its total capacity, holding 1.77 hm³ of water out of a maximum 2.23 hm³. At this level the reservoir is within its normal operating range.
Over the most recent week on record the fill level has fallen by 1.3 percentage points, and it is 9.8 points below its level on the same date a year earlier.
Across the readings we hold for Gray Reef Reservoir — 1824 data points between October 30, 2021 and October 27, 2026 — the level has ranged from a low of 9.0% (March 2, 2026) to a high of 102.7% (March 27, 2023). On average the reservoir is fullest around April and at its lowest around October.
It is operated by BOR primarily for multiple purposes. It is at 42.566°N, 106.699°W.
Key facts
- Current fill level
- 79.4% of total capacity
- Water stored
- 1.77 hm³
- Total capacity
- 2.23 hm³
- 7-day change
- ▼ 1.3 pp
- Year-on-year
- ▼ 9.8 pp
- Primary use
- Multipurpose
- Operator
- BOR
- Coordinates
- 42.566°N, 106.699°W
- Last updated
- October 27, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 27 Oct 2026 | 79.4% | 1.77 |
| 26 Oct 2026 | 82.1% | 1.83 |
| 25 Oct 2026 | 78.5% | 1.75 |
| 24 Oct 2026 | 82.1% | 1.83 |
| 23 Oct 2026 | 81.2% | 1.81 |
| 22 Oct 2026 | 80.7% | 1.8 |
| 21 Oct 2026 | 80.3% | 1.79 |
| 20 Oct 2026 | 80.7% | 1.8 |
| 19 Oct 2026 | 81.6% | 1.82 |
| 18 Oct 2026 | 79.8% | 1.78 |
| 17 Oct 2026 | 78.0% | 1.74 |
| 16 Oct 2026 | 79.4% | 1.77 |