I 15 over Sep Lyons Creek Road
GoodLewis and Clark County, Montana · 6M S Wolf Creek · Structure no. I00015220+04981
- Built
- 1964
- 61 years old
- Condition
- Good
- inspected July 2024
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 134 ft
- 3 main spans
- Daily traffic
- 2,555
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
I 15 over Sep Lyons Creek Road is a prestressed concrete stringer/multi-beam or girder carrying I 15 over Sep Lyons Creek Road in Lewis and Clark County, Montana. It was built in 1964, so it is 61 years old, older than the Montana average of 47 years.
The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
It carries about 2,555 vehicles a day, roughly 21% of them trucks, projected to reach 2,771 by 2043. The structure is 134 ft (40.8 m) long and 35 ft wide.
Location
Open in Google MapsCondition and inspection
All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 8 Very Good | No problems noted. |
| Superstructure | 8 Very Good | No problems noted. |
| Substructure | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was I 15 over Sep Lyons Creek Road built?
It was built in 1964, making it 61 years old in 2025.
What condition is I 15 over Sep Lyons Creek Road in?
The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in July 2024.
How much traffic does I 15 over Sep Lyons Creek Road carry?
About 2,555 vehicles per day (2023 count), of which roughly 21% are trucks.
How long is I 15 over Sep Lyons Creek Road?
The structure is 134 ft (40.8 m) long with a longest span of 52 ft (15.7 m) and a deck 35 ft wide.
Who owns I 15 over Sep Lyons Creek Road?
It is owned by the State Highway Agency.