I 15 Frontage RD over Boulder River 042
FairJefferson County, Montana · Basin · Structure no. L22099009+02001
- Built
- 1985
- 40 years old
- Condition
- Fair
- inspected July 2023
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 106 ft
- 1 main span
- Daily traffic
- 100
- 2025 count
- Owner
- State
- State Highway Agency
About this bridge
I 15 Frontage RD over Boulder River 042 is a prestressed concrete stringer/multi-beam or girder carrying I 15 Frontage RD over Boulder River 042 in Jefferson County, Montana. It was built in 1985, so it is 40 years old, younger 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 100 vehicles a day, roughly 3% of them trucks, projected to reach 100 by 2040. The structure is 106 ft (32.3 m) long and 27 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 | 7 Good | Some minor problems. |
| Superstructure | 7 Good | Some minor problems. |
| 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 I 15 Frontage RD over Boulder River 042 built?
It was built in 1985, making it 40 years old in 2025.
What condition is I 15 Frontage RD over Boulder River 042 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 July 2023.
How much traffic does I 15 Frontage RD over Boulder River 042 carry?
About 100 vehicles per day (2025 count), of which roughly 3% are trucks.
How long is I 15 Frontage RD over Boulder River 042?
The structure is 106 ft (32.3 m) long with a longest span of 105 ft (32 m) and a deck 27 ft wide.
Who owns I 15 Frontage RD over Boulder River 042?
It is owned by the State Highway Agency.