Reservoir · Montana · United States · USACE CWMS
Clark Canyon Dam & Reservoir
34.7% full
Capacity
219.64 hm³
Volume stored
76 hm³
Vs month average
79% of normal
Coordinates
45.001°N, 112.859°W
Last updated
2026-10-27
Current fill
34.7%vs 7 days ago
+1.6 ppgaining
vs 1 year ago
-0.3 ppyear-over-year
7-day trend
↑rising
Drought context
Storage vs October average
79%of normal
34.7% full on 2026-10-27, against an average of 44.1% for October across 6 years of readings (-9.4 points).
Drought Monitor at this site · 20 October 2026
Nonenot in a drought category
Clark Canyon Dam & Reservoir's coordinates fall outside every category on the weekly U.S. Drought Monitor map. That describes local conditions — rainfall, soil moisture, streamflow — not the reservoir's storage. Montana drought figures →
Data source: USACE CWMS — US Army Corps of Engineers — 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. 45.001°N, 112.859°W · Open in Google Maps
About Clark Canyon Dam & Reservoir
As of October 27, 2026, Clark Canyon Dam & Reservoir is filled to 34.7% of its total capacity, holding 76.3 hm³ of water out of a maximum 219.64 hm³. At this level the reservoir is low.
Over the most recent week on record the fill level has risen by 1.6 percentage points, and it sits close to where it was a year earlier.
Across the readings we hold for Clark Canyon Dam & Reservoir — 1821 data points between October 29, 2021 and October 27, 2026 — the level has ranged from a low of 25.9% (September 6, 2022) to a high of 98.7% (April 11, 2024). On average the reservoir is fullest around May and at its lowest around September.
It is operated by USACE primarily for multiple purposes. It is at 45.001°N, 112.859°W.
Key facts
- Current fill level
- 34.7% of total capacity
- Water stored
- 76.3 hm³
- Total capacity
- 219.64 hm³
- 7-day change
- ▲ 1.6 pp
- Year-on-year
- ▼ 0.3 pp
- Primary use
- Multipurpose
- Operator
- USACE
- Coordinates
- 45.001°N, 112.859°W
- Last updated
- October 27, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 27 Oct 2026 | 34.7% | 76.3 |
| 26 Oct 2026 | 34.5% | 75.78 |
| 25 Oct 2026 | 34.3% | 75.3 |
| 24 Oct 2026 | 34.0% | 74.78 |
| 23 Oct 2026 | 33.6% | 73.79 |
| 22 Oct 2026 | 33.4% | 73.45 |
| 21 Oct 2026 | 33.3% | 73.11 |
| 20 Oct 2026 | 33.1% | 72.71 |
| 19 Oct 2026 | 32.9% | 72.37 |
| 18 Oct 2026 | 32.8% | 72 |
| 17 Oct 2026 | 32.6% | 71.67 |
| 16 Oct 2026 | 32.4% | 71.27 |