Martinsdale, East Dam
Martinsdale, East Dam is an earth dam located in Wheatland County, Montana, built in 1939. It carries a High hazard potential classification and has a poor condition assessment.
About Martinsdale, East Dam
The primary purpose of Martinsdale, East Dam is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by State Water Projects (state). It impounds the Tr-musselshell River near Two Dot.
The dam stands 49 feet tall and stretches 1,550 feet across, creates a reservoir covering 985 acres, has a maximum storage capacity of 38,958 acre-feet, and collects water from a drainage area of 15 square miles. Completed in 1939, 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 poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. An emergency action plan is in place for this dam. The most recent inspection on record was 10/10/2024.
At 49 feet, this dam is taller than 92% of dams nationwide.
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 | Wheatland |
| Nearest City | Two Dot |
| River/Stream | Tr-musselshell River |
| Coordinates | 46.44260, -110.25970 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 49 ft |
| Dam Height | 49 ft |
| Dam Length | 1,550 ft |
| Year Completed | 1939 (87 years old) |
Storage & Hydraulics
| NID Storage | 38,958 acre-ft |
| Max Storage | 38,958 acre-ft |
| Normal Storage | 32,348 acre-ft |
| Surface Area | 985 acres |
| Drainage Area | 15 sq mi |
| Max Discharge | 1,060 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | STATE WATER PROJECTS |
| Owner Type | State |
| Hazard Classification | High |
| Condition Assessment | Poor |
| Last Inspection | 10/10/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MT00007 |
| Federal ID | MT00007 |
| More Info | State Dam Safety Program |