Reservoir · Wyoming · United States · BOR RISE
Gray Reef Reservoir
Gray Reef Reservoir and Dam
89.7% full
Capacity
2.23 hm³
Volume stored
2 hm³
Coordinates
42.566°N, 106.699°W
Last updated
2026-09-08
Current fill
89.7%vs 7 days ago
+2.7%gaining
vs 1 year ago
-0.4%year-over-year
7-day trend
↑rising
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: 2026-09-08.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 42.566, -106.699 · Open in Google Maps
About Gray Reef Reservoir
As of September 8, 2026, Gray Reef Reservoir is filled to 89.7% of its total capacity, holding roughly 2 hm³ of water out of a maximum 2 hm³. At this level the reservoir is high.
Over the most recent week on record the fill level has risen by 2.7 percentage points, and it sits close to where it was a year earlier.
Across the readings we hold for Gray Reef Reservoir — 1823 data points between September 12, 2021 and September 8, 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 February.
It is operated by BOR primarily for multiple purposes. It lies within the Wyoming basin at 42.566°N, 106.699°W.
Key facts
- Current fill level
- 89.7%
- Water stored
- 2 hm³
- Total capacity
- 2 hm³
- 7-day change
- ▲ 2.7 pts
- Year-on-year
- ▼ 0.4 pts
- Primary use
- Multipurpose
- River basin
- Wyoming
- Operator
- BOR
- Coordinates
- 42.566°N, 106.699°W
- Last updated
- September 8, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 8 Sep 2026 | 89.7% | 2 |
| 7 Sep 2026 | 87.9% | 2 |
| 6 Sep 2026 | 85.2% | 2 |
| 5 Sep 2026 | 87.0% | 2 |
| 4 Sep 2026 | 89.7% | 2 |
| 3 Sep 2026 | 90.1% | 2 |
| 2 Sep 2026 | 88.8% | 2 |
| 1 Sep 2026 | 87.0% | 2 |
| 31 Aug 2026 | 85.2% | 2 |
| 30 Aug 2026 | 83.9% | 2 |
| 29 Aug 2026 | 83.4% | 2 |
| 28 Aug 2026 | 82.1% | 2 |