S 59 over South Fork Sunday Creek
Custer County, Montana · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- S 59 over South Fork Sunday Creek in Custer County, Montana, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 1930 and reconstructed in 1963, making it 95 years old at the 2025 inventory.
- It carries about 1,474 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 54 of the 71 inventoried bridges in Custer County rated fair (76.1%); 6 (8.5%) are rated poor.
- 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 → (46.44842, -105.90328)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 6 | Satisfactory condition |
| Superstructure | 6 | Satisfactory condition |
| Substructure | 6 | Satisfactory condition |
Bridge details
| Structure | Concrete tee beam |
| Length | about 164 ft |
| Location | 3M NW Miles City |
| NBI structure number | P00018003+09001 |
| Condition class | Fair |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Montana department of transportation.
Busiest bridges in Custer County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I 94 over Lignite Creek | 1964 | 4,724 | Fair |
| I 94 over Coal Creek | 1963 | 4,724 | Fair |
| I 94 over Tongue River | 1961 | 4,707 | Fair |
| I 94 over Vehicle Pass | 1986 | 4,697 | Good |
| I 94 over Jones Creek-stockpass | 1962 | 4,393 | Fair |
| S 59 over Yellowstone River | 1957 | 2,949 | Fair |
All bridges nearby: Custer County, MT bridge conditions · every bridge in Custer County · Montana bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.