Sun River Diversion Dam
Sun River Diversion Dam is a concrete dam located in Teton County, Montana, built in 1915. It carries a High hazard potential classification.
About Sun River Diversion Dam
The primary purpose of Sun River Diversion Dam is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Bureau Of Reclamation (federal). It impounds the North Fork Sun River near Simms.
The dam stands 132 feet tall and stretches 261 feet across, creates a reservoir covering 202 acres, has a maximum storage capacity of 6,395 acre-feet, and collects water from a drainage area of 600 square miles. Completed in 1915, the structure is over a century old.
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. The most recent inspection on record was 09/09/2020.
At 132 feet, this dam is taller than 99% 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 | Teton |
| Nearest City | Simms |
| River/Stream | North Fork Sun River |
| Coordinates | 47.62110, -112.70670 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 132 ft |
| Dam Height | 132 ft |
| Dam Length | 261 ft |
| Year Completed | 1915 (111 years old) |
Storage & Hydraulics
| NID Storage | 6,395 acre-ft |
| Max Storage | 6,395 acre-ft |
| Normal Storage | 6,395 acre-ft |
| Surface Area | 202 acres |
| Drainage Area | 600 sq mi |
| Max Discharge | 34,000 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | BUREAU OF RECLAMATION |
| Owner Type | Federal |
| Hazard Classification | High |
| Condition Assessment | Not Available |
| Last Inspection | 09/09/2020 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | MT00585 |
| Federal ID | MT00585 |
| More Info | State Dam Safety Program |