Jawbone Dike #1
Jawbone Dike #1 is an earth dam located in Wheatland County, Montana, built in 1966. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Jawbone Dike #1
The primary purpose of Jawbone Dike #1 is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by City Of Harlowton (local government). It impounds the Jawbone Creek near Harlowton.
The dam stands 13 feet tall and stretches 780 feet across, has a maximum storage capacity of 1,933 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1966, the structure is well into its service life at over 50 years 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. 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 04/01/2020.
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 | Harlowton |
| River/Stream | Jawbone Creek |
| Coordinates | 46.44230, -109.84059 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 13 ft |
| Dam Height | 13 ft |
| Dam Length | 780 ft |
| Year Completed | 1966 (60 years old) |
Storage & Hydraulics
| NID Storage | 1,933 acre-ft |
| Max Storage | 1,933 acre-ft |
| Drainage Area | 1 sq mi |
| Max Discharge | 140 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | CITY OF HARLOWTON |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 04/01/2020 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MT00785 |
| Federal ID | MT00070S001 |
| More Info | State Dam Safety Program |