Reservoir · Montana · United States · BOR RISE
Gibson Reservoir
Gibson Reservoir and Dam
7.7% full
Capacity
122.19 hm³
Volume stored
9 hm³
Coordinates
47.601°N, 112.762°W
Last updated
2026-09-09
Current fill
7.7%vs 7 days ago
+1.9%gaining
vs 1 year ago
+2.1%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: 2026-09-09.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 47.601, -112.762 · Open in Google Maps
About Gibson Reservoir
As of September 9, 2026, Gibson Reservoir is filled to 7.7% of its total capacity, holding roughly 9 hm³ of water out of a maximum 122 hm³. At this level the reservoir is critically low.
Over the most recent week on record the fill level has risen by 1.9 percentage points, and it is 2.1 points above its level on the same date a year earlier.
Across the readings we hold for Gibson Reservoir — 2016 data points between September 12, 2021 and September 9, 2026 — the level has ranged from a low of 4.7% (February 14, 2025) to a high of 99.7% (June 21, 2022). On average the reservoir is fullest around June and at its lowest around September.
It is operated by BOR primarily for multiple purposes. It lies within the Montana basin at 47.601°N, 112.762°W.
Key facts
- Current fill level
- 7.7%
- Water stored
- 9 hm³
- Total capacity
- 122 hm³
- 7-day change
- ▲ 1.9 pts
- Year-on-year
- ▲ 2.1 pts
- Primary use
- Multipurpose
- River basin
- Montana
- Operator
- BOR
- Coordinates
- 47.601°N, 112.762°W
- Last updated
- September 9, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 9 Sep 2026 | 7.7% | 9 |
| 8 Sep 2026 | 7.3% | 9 |
| 7 Sep 2026 | 6.7% | 8 |
| 6 Sep 2026 | 6.0% | 7 |
| 5 Sep 2026 | 5.7% | 7 |
| 4 Sep 2026 | 5.6% | 7 |
| 3 Sep 2026 | 5.6% | 7 |
| 2 Sep 2026 | 5.8% | 7 |
| 1 Sep 2026 | 7.3% | 9 |
| 31 Aug 2026 | 9.5% | 12 |
| 30 Aug 2026 | 11.8% | 14 |
| 29 Aug 2026 | 14.0% | 17 |