Overnight Reservoir is an earth dam located in Beaverhead County, Montana, built in 1920. It carries a Low hazard potential classification.
Dam profile
NID height · 17 ft17 ft tall and 850 ft long. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.
About Overnight Reservoir
The primary purpose of Overnight Reservoir is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Beaverhead Water Co (private). It impounds the Tr-cave Gulch near Glen.
The dam stands 17 feet tall and stretches 850 feet across, and has a maximum storage capacity of 88 acre-feet. Completed in 1920, the structure is over a century 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.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Montana |
| County | Beaverhead |
| Nearest City | Glen |
| River/Stream | Tr-cave Gulch |
| Coordinates | 45.32780, -112.72520 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 17 ft |
| Dam Height | 17 ft |
| Dam Length | 850 ft |
| Year Completed | 1920 (106 years old) |
Storage & Hydraulics
| NID Storage | 88 acre-ft |
| Max Storage | 88 acre-ft |
| Normal Storage | 21 acre-ft |
Ownership & Safety
| Purpose | Irrigation |
| Owner | Beaverhead Water Co |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Not assessed |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | MT03323 |
| Federal ID | MT03323 |
| More Info | State Dam Safety Program |