Irr Bia Rte 55 over Box Elder Creek
Hill County, Montana · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Irr Bia Rte 55 over Box Elder Creek in Hill County, Montana, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 7 (good condition) on the 0-9 scale.
- It was built in 2003, making it 22 years old at the 2025 inventory.
- It carries about 10 vehicles a day (traffic count year 2024).
- It is one of 27 of the 46 inventoried bridges in Hill County rated good (58.7%); 3 (6.5%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated October 2024, on a 24-month routine inspection cycle.
- A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.
View this bridge on a map → (48.28067, -109.81667)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Culvert | 7 | 7 | Good condition |
Bridge details
| Structure | Concrete culvert |
| Length | about 24 ft |
| Location | 3.6 Km NW of Rocky Boys |
| NBI structure number | 00000000000C919 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | October 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Montana department of transportation.
Busiest bridges in Hill County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 2 over Little Box Elder Creek | 2011 | 3,678 | Good |
| US 2 over Drainage | 2011 | 3,678 | Good |
| US 2 over RR | 1960 | 3,539 | Fair |
| 7TH Ave N over RR | 1936 | 3,404 | Fair |
| US 87 over Beaver Creek | 1966 | 2,982 | Good |
| 7TH Ave N over Milk River | 1973 | 2,952 | Good |
All bridges nearby: Hill County, MT bridge conditions · every bridge in Hill County · Montana bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.