Big John M
Big John M is an earth dam located in Fergus County, Montana, built in 1972. It carries a Low hazard potential classification.
About Big John M
The primary purpose of Big John M is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Cj/maralyn Montgomery (private). It impounds the Tr-east Fork Armells Creek near Christina.
The dam stands 52 feet tall and stretches 210 feet across, has a maximum storage capacity of 1,003 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1972, the structure is well into its service life at over 50 years old.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life.
At 52 feet, this dam is taller than 93% of dams nationwide.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Montana |
| County | Fergus |
| Nearest City | Christina |
| River/Stream | Tr-east Fork Armells Creek |
| Coordinates | 47.28790, -109.21700 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 52 ft |
| Dam Height | 52 ft |
| Dam Length | 210 ft |
| Year Completed | 1972 (54 years old) |
Storage & Hydraulics
| NID Storage | 1,003 acre-ft |
| Max Storage | 1,003 acre-ft |
| Normal Storage | 281 acre-ft |
| Drainage Area | 0 sq mi |
| Max Discharge | 2,250 cfs |
Ownership & Safety
| Purpose | Irrigation |
| Owner | CJ/MARALYN MONTGOMERY |
| Owner Type | Private |
| Hazard Classification | Low |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | MT03096 |
| Federal ID | MT03096 |
| More Info | State Dam Safety Program |