Galena Gulch Road over Boulder River
Jefferson County, Montana · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Galena Gulch Road over Boulder River in Jefferson County, Montana, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1957, making it 68 years old at the 2025 inventory.
- It carries about 50 vehicles a day.
- It is one of 103 of the 136 inventoried bridges in Jefferson County rated fair (75.7%); 7 (5.1%) 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 September 2024, on a 24-month routine inspection cycle.
- A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.
View this bridge on a map → (46.25399, -112.1829)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 5 | 5 | Fair condition |
Bridge details
| Structure | Timber stringer or multi-beam girder |
| Length | about 71 ft |
| Location | I15 High Ore Exit |
| NBI structure number | 010902000000036 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | September 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 4: foundations stable, field review says exposed foundations need protection |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Montana department of transportation.
Busiest bridges in Jefferson County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I 15 over Prickly Pear Creek | 1969 | 5,987 | Fair |
| I 15 over Prickly Pear Creek | 1969 | 5,987 | Fair |
| S 518 over Int Montana City-i 15 | 1968 | 5,885 | Good |
| I 90 over Int Cardwell-s 359 | 1968 | 5,599 | Fair |
| I 90 over Int Cardwell-s 359 | 1968 | 5,599 | Fair |
| I 90 Eastbound over Boulder River | 1968 | 5,599 | Good |
All bridges nearby: Jefferson County, MT bridge conditions · every bridge in Jefferson County · Montana bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.