Reservoir · Montana · United States · USACE CWMS
Clark Canyon Dam & Reservoir
35.3% full
Capacity
219.64 hm³
Volume stored
78 hm³
Coordinates
45.001°N, 112.859°W
Last updated
2026-07-29
Current fill
35.3%vs 7 days ago
-0.3%losing
vs 1 year ago
-15.5%year-over-year
7-day trend
→stable
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: 2026-07-29.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 45.001, -112.859 · Open in Google Maps
About Clark Canyon Dam & Reservoir
As of July 29, 2026, Clark Canyon Dam & Reservoir is filled to 35.3% of its total capacity, holding roughly 78 hm³ of water out of a maximum 220 hm³. At this level the reservoir is low.
Over the most recent week on record the fill level has held broadly steady (-0.3 pts), and it is 15.5 points below its level on the same date a year earlier.
Across the readings we hold for Clark Canyon Dam & Reservoir — 1818 data points between July 31, 2021 and July 29, 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 lies within the Montana basin at 45.001°N, 112.859°W.
Key facts
- Current fill level
- 35.3%
- Water stored
- 78 hm³
- Total capacity
- 220 hm³
- 7-day change
- ▼ 0.3 pts
- Year-on-year
- ▼ 15.5 pts
- Primary use
- Multipurpose
- River basin
- Montana
- Operator
- USACE
- Coordinates
- 45.001°N, 112.859°W
- Last updated
- July 29, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 29 Jul 2026 | 35.3% | 78 |
| 28 Jul 2026 | 35.6% | 78 |
| 27 Jul 2026 | 35.9% | 79 |
| 26 Jul 2026 | 36.2% | 80 |
| 25 Jul 2026 | 36.5% | 80 |
| 24 Jul 2026 | 36.8% | 81 |
| 23 Jul 2026 | 37.1% | 81 |
| 22 Jul 2026 | 37.3% | 82 |
| 21 Jul 2026 | 37.6% | 83 |
| 20 Jul 2026 | 38.0% | 84 |
| 19 Jul 2026 | 38.4% | 84 |
| 18 Jul 2026 | 38.7% | 85 |
Frequently asked questions
What is the current water level of Clark Canyon Dam & Reservoir?
As of July 29, 2026, Clark Canyon Dam & Reservoir is at 35.3% of its capacity, holding approximately 78 hm³ of water, according to USACE CWMS (US Army Corps of Engineers) data.
Is Clark Canyon Dam & Reservoir reservoir full?
No. As of July 29, 2026, Clark Canyon Dam & Reservoir is low at 35.3% of its capacity, so it is not full.
Is the water level at Clark Canyon Dam & Reservoir rising or falling?
The level at Clark Canyon Dam & Reservoir has been broadly stable over the latest week on record (-0.3 points).
How much water can Clark Canyon Dam & Reservoir hold?
Clark Canyon Dam & Reservoir has a total capacity of 220 hm³.
Where is Clark Canyon Dam & Reservoir reservoir located?
Clark Canyon Dam & Reservoir is located in Montana, United States, within the Montana basin (coordinates 45.001°N, 112.859°W).
What is Clark Canyon Dam & Reservoir used for?
Clark Canyon Dam & Reservoir is used primarily for multiple purposes, and is managed by USACE.