I 15 over Sep Park Street
FairBeaverhead County, Montana · Dillon · Structure no. I00015063+04942
- Built
- 1983
- 42 years old
- Condition
- Fair
- inspected November 2023
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 184 ft
- 3 main spans
- Daily traffic
- 2,636
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
I 15 over Sep Park Street is a prestressed concrete stringer/multi-beam or girder carrying I 15 over Sep Park Street in Beaverhead County, Montana. It was built in 1983, so it is 42 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 2,636 vehicles a day, roughly 25% of them trucks, projected to reach 2,872 by 2043. The structure is 184 ft (56.2 m) long and 45 ft wide. If it were closed, the detour would be 1.2 mi (2 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 | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was I 15 over Sep Park Street built?
It was built in 1983, making it 42 years old in 2025.
What condition is I 15 over Sep Park Street 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 November 2023.
How much traffic does I 15 over Sep Park Street carry?
About 2,636 vehicles per day (2023 count), of which roughly 25% are trucks.
How long is I 15 over Sep Park Street?
The structure is 184 ft (56.2 m) long with a longest span of 74 ft (22.7 m) and a deck 45 ft wide.
Who owns I 15 over Sep Park Street?
It is owned by the State Highway Agency.