Morony
Morony is a gravity dam located in Cascade County, Montana, built in 1929. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Morony
The primary purpose of Morony is hydroelectric. The dam generates hydroelectric power by channeling water through turbines, converting the energy of flowing water into electricity. The dam is owned by Northwestern Energy (private). It impounds the Missouri River near Fort Benton.
The dam stands 107 feet tall and stretches 842 feet across, creates a reservoir covering 304 acres, has a maximum storage capacity of 13,889 acre-feet, and collects water from a drainage area of 23,292 square miles. Completed in 1929, the structure is well-established, with more than 75 years of service.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 09/10/2024.
At 107 feet, this dam is taller than 98% of all dams in the United States.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Montana dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Montana |
| County | Cascade |
| Nearest City | Fort Benton |
| River/Stream | Missouri River |
| Coordinates | 47.58140, -111.05990 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 107 ft |
| Dam Height | 70 ft |
| Dam Length | 842 ft |
| Year Completed | 1929 (97 years old) |
Storage & Hydraulics
| NID Storage | 13,889 acre-ft |
| Max Storage | 13,889 acre-ft |
| Normal Storage | 13,598 acre-ft |
| Surface Area | 304 acres |
| Drainage Area | 23,292 sq mi |
| Max Discharge | 153,000 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | NorthWestern Energy |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 09/10/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MT00563 |
| Federal ID | MT00563 |
| More Info | State Dam Safety Program |