Reservoir · Wyoming · United States · BOR RISE
Bull Lake Reservoir
Bull Lake Reservoir and Dam
56.2% full
Capacity
188.06 hm³
Volume stored
106 hm³
Coordinates
43.210°N, 109.042°W
Last updated
2026-09-09
Current fill
56.2%vs 7 days ago
-5.5%losing
vs 1 year ago
+37.7%year-over-year
7-day trend
↓falling
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. 43.210, -109.042 · Open in Google Maps
About Bull Lake Reservoir
As of September 9, 2026, Bull Lake Reservoir is filled to 56.2% of its total capacity, holding roughly 106 hm³ of water out of a maximum 188 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 5.5 percentage points, and it is 37.7 points above its level on the same date a year earlier.
Across the readings we hold for Bull Lake Reservoir — 1950 data points between September 12, 2021 and September 9, 2026 — the level has ranged from a low of 17.8% (September 2, 2025) to a high of 98.9% (July 17, 2022). On average the reservoir is fullest around July and at its lowest around November.
It is operated by BOR primarily for multiple purposes. It lies within the Wyoming basin at 43.210°N, 109.042°W.
Key facts
- Current fill level
- 56.2%
- Water stored
- 106 hm³
- Total capacity
- 188 hm³
- 7-day change
- ▼ 5.5 pts
- Year-on-year
- ▲ 37.7 pts
- Primary use
- Multipurpose
- River basin
- Wyoming
- Operator
- BOR
- Coordinates
- 43.210°N, 109.042°W
- Last updated
- September 9, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 9 Sep 2026 | 56.2% | 106 |
| 8 Sep 2026 | 57.2% | 108 |
| 7 Sep 2026 | 58.1% | 109 |
| 6 Sep 2026 | 59.0% | 111 |
| 5 Sep 2026 | 59.8% | 112 |
| 4 Sep 2026 | 60.5% | 114 |
| 3 Sep 2026 | 61.2% | 115 |
| 2 Sep 2026 | 61.7% | 116 |
| 1 Sep 2026 | 62.1% | 117 |
| 31 Aug 2026 | 62.5% | 118 |
| 30 Aug 2026 | 62.7% | 118 |
| 29 Aug 2026 | 63.2% | 119 |