IRR - US 89 over ST Marys River
FairGlacier County, Montana · 2M SE Babb · Structure no. P00058038+06171
- Built
- 1956
- 69 years old, rebuilt 1998
- Condition
- Fair
- inspected October 2023
- Type
- Stringer/Multi-beam or Girder
- Steel Continuous
- Length
- 313 ft
- 3 main spans
- Daily traffic
- 2,355
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
IRR - US 89 over ST Marys River is a steel continuous stringer/multi-beam or girder carrying IRR - US 89 over ST Marys River in Glacier County, Montana. It was built in 1956 and reconstructed in 1998, so it is 69 years old, older than the Montana average of 47 years.
The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
It carries about 2,355 vehicles a day, roughly 1% of them trucks, projected to reach 2,473 by 2043. The structure is 313 ft (95.4 m) long and 31 ft wide. If it were closed, the detour would be 123.7 mi (199 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 6 Satisfactory | Structural elements show some minor deterioration. |
| Superstructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Channel and channel protection | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was IRR - US 89 over ST Marys River built?
It was built in 1956, making it 69 years old in 2025. It was reconstructed in 1998.
What condition is IRR - US 89 over ST Marys River in?
The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in October 2023.
How much traffic does IRR - US 89 over ST Marys River carry?
About 2,355 vehicles per day (2023 count), of which roughly 1% are trucks.
How long is IRR - US 89 over ST Marys River?
The structure is 313 ft (95.4 m) long with a longest span of 120 ft (36.6 m) and a deck 31 ft wide.
Who owns IRR - US 89 over ST Marys River?
It is owned by the State Highway Agency.