I 90 over Ronan Ranch Road
Stillwater County, Montana · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- I 90 over Ronan Ranch Road in Stillwater County, Montana, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1970, making it 55 years old at the 2025 inventory.
- It carries about 6,161 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 63 of the 92 inventoried bridges in Stillwater County rated fair (68.5%); 1 (1.1%) 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 → (45.60034, -109.06192)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 5 | Fair condition |
| Superstructure | 5 | Fair condition |
| Substructure | 6 | Satisfactory condition |
Bridge details
| Structure | Continuous concrete slab |
| Length | about 79 ft |
| Location | 7.4M W Park City |
| NBI structure number | I00090419+00262 |
| Condition class | Fair |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Montana department of transportation.
Busiest bridges in Stillwater County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I 90 over Cove Irrigation Ditch | 1970 | 12,321 | Good |
| I 90 over Int Exit 396 | 1963 | 10,845 | Fair |
| I 90 over Int Park City | 1967 | 7,580 | Fair |
| I 90 over Int Park City | 1967 | 7,580 | Fair |
| I 90 over Sep Pope Road | 1967 | 7,580 | Fair |
| I 90 over Sep Pope Road | 1967 | 7,580 | Fair |
All bridges nearby: Stillwater County, MT bridge conditions · every bridge in Stillwater County · Montana bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.