Reservoir · Wyoming · United States · BOR RISE
Keyhole Reservoir
Keyhole Reservoir and Dam
25.0% full
Capacity
412.25 hm³
Volume stored
103 hm³
Coordinates
44.382°N, 104.779°W
Last updated
2026-09-09
Current fill
25.0%vs 7 days ago
-0.2%losing
vs 1 year ago
-8.8%year-over-year
7-day trend
→stable
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: 2026-09-09.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 44.382, -104.779 · Open in Google Maps
About Keyhole Reservoir
As of September 9, 2026, Keyhole Reservoir is filled to 25.0% of its total capacity, holding roughly 103 hm³ of water out of a maximum 412 hm³. At this level the reservoir is low.
Over the most recent week on record the fill level has held broadly steady (-0.2 pts), and it is 8.8 points below its level on the same date a year earlier.
Across the readings we hold for Keyhole Reservoir — 1952 data points between September 12, 2021 and September 9, 2026 — the level has ranged from a low of 25.0% (September 8, 2026) to a high of 40.5% (June 11, 2022). On average the reservoir is fullest around June and at its lowest around August.
It is operated by BOR primarily for multiple purposes. It lies within the Wyoming basin at 44.382°N, 104.779°W.
Key facts
- Current fill level
- 25.0%
- Water stored
- 103 hm³
- Total capacity
- 412 hm³
- 7-day change
- ▼ 0.2 pts
- Year-on-year
- ▼ 8.8 pts
- Primary use
- Multipurpose
- River basin
- Wyoming
- Operator
- BOR
- Coordinates
- 44.382°N, 104.779°W
- Last updated
- September 9, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 9 Sep 2026 | 25.0% | 103 |
| 8 Sep 2026 | 25.0% | 103 |
| 7 Sep 2026 | 25.1% | 103 |
| 6 Sep 2026 | 25.1% | 104 |
| 5 Sep 2026 | 25.2% | 104 |
| 4 Sep 2026 | 25.2% | 104 |
| 3 Sep 2026 | 25.2% | 104 |
| 2 Sep 2026 | 25.2% | 104 |
| 1 Sep 2026 | 25.3% | 104 |
| 31 Aug 2026 | 25.3% | 104 |
| 30 Aug 2026 | 25.4% | 105 |
| 29 Aug 2026 | 25.4% | 105 |