Trident RD over Gallatin River
FairGallatin County, Montana · 1M SW Trident · Structure no. S00286003+00001
- Built
- 1975
- 50 years old
- Condition
- Fair
- inspected September 2024
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 184 ft
- 2 main spans
- Daily traffic
- 496
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
Trident RD over Gallatin River is a prestressed concrete stringer/multi-beam or girder carrying Trident RD over Gallatin River in Gallatin County, Montana. It was built in 1975, so it is 50 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 5 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 496 vehicles a day, roughly 6% of them trucks, projected to reach 521 by 2043. The structure is 184 ft (56.1 m) long and 34 ft wide. If it were closed, the detour would be 13 mi (21 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 | 7 Good | Some minor problems. |
| Substructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Channel and channel protection | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Trident RD over Gallatin River built?
It was built in 1975, making it 50 years old in 2025.
What condition is Trident RD over Gallatin 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 September 2024.
How much traffic does Trident RD over Gallatin River carry?
About 496 vehicles per day (2023 count), of which roughly 6% are trucks.
How long is Trident RD over Gallatin River?
The structure is 184 ft (56.1 m) long with a longest span of 92 ft (28 m) and a deck 34 ft wide.
Who owns Trident RD over Gallatin River?
It is owned by the State Highway Agency.