Rainbow
High HazardSatisfactory ConditionEmergency Action Plan: Yes
Location
| State | Montana |
| County | Cascade |
| Nearest City | Fort Benton |
| River/Stream | Missouri River |
| Coordinates | 47.53430, -111.20520 |
Physical Characteristics
| Dam Type | Other |
| NID Height | 44 ft |
| Dam Height | 44 ft |
| Dam Length | 1,405 ft |
| Year Completed | 1910 (116 years old) |
Storage & Hydraulics
| NID Storage | 1,237 acre-ft |
| Max Storage | 1,237 acre-ft |
| Normal Storage | 1,237 acre-ft |
| Surface Area | 126 acres |
| Drainage Area | 22,928 sq mi |
| Max Discharge | 125,000 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | NorthWestern Energy |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 08/10/2022 |
| Emergency Action Plan | Yes |