Irr Bia Rte 123 over South Fork Valley Creek
Sanders County, Montana · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Irr Bia Rte 123 over South Fork Valley Creek in Sanders County, Montana, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 3 (serious condition) on the 0-9 scale.
- It was built in 1995 and reconstructed in 2011, making it 30 years old at the 2025 inventory.
- It carries about 20 vehicles a day (traffic count year 2021).
- It is one of 10 of the 120 inventoried bridges in Sanders County rated poor (8.3%); 10 (8.3%) are rated poor.
- Its traffic status in the 2025 inventory is open, posting recommended but not legally implemented (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated January 2021, on a 24-month routine inspection cycle.
- A poor rating means at least one major component - deck, superstructure, or substructure - is rated 4 or lower on FHWA's 0-9 scale. It does not by itself mean the bridge is unsafe; bridges judged unsafe are closed or load-restricted by their owners.
View this bridge on a map → (47.1835, -114.21435)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 3 | 3 | Serious condition |
| Substructure | 8 | 8 | Very good condition |
Bridge details
| Structure | Timber stringer or multi-beam girder |
| Length | about 27 ft |
| Location | 10.3 Km From US Hwy 93 |
| NBI structure number | 00000000000P839 |
| Condition class | Poor |
| Traffic status (item 41) | Open, posting recommended but not legally implemented |
| Last inspection (item 90) | January 2021 |
| 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 Sanders County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| S 200 over Clark Fork River | 1997 | 3,009 | Fair |
| S 200 over Clark Fork River | 1996 | 3,009 | Fair |
| S 200 over RR | 2000 | 2,686 | Good |
| S 200 over Clark Fork River | 1960 | 2,482 | Poor |
| Irr - S 28 over Hot Springs Creek | 1959 | 2,181 | Fair |
| S 200 over Wildlife Crossing | 2019 | 2,177 | Good |
All bridges nearby: Sanders County, MT bridge conditions · every bridge in Sanders County · Montana bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.