Old HWY 312 over Twelve Mile Creek 169
FairPosted for loadYellowstone County, Montana · 2M W Huntley · Structure no. L56788010+03001
- Built
- 1947
- 78 years old
- Condition
- Fair
- inspected October 2024
- Type
- Stringer/Multi-beam or Girder
- Wood or Timber
- Length
- 101 ft
- 4 main spans
- Daily traffic
- 4,005
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
Old HWY 312 over Twelve Mile Creek 169 is a wood or timber stringer/multi-beam or girder carrying Old HWY 312 over Twelve Mile Creek 169 in Yellowstone County, Montana. It was built in 1947, so it is 78 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. Its operating status is: posted for load restriction.
It carries about 4,005 vehicles a day, roughly 2% of them trucks, projected to reach 4,205 by 2043. The structure is 101 ft (30.7 m) long and 32 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 | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Substructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Channel and channel protection | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Old HWY 312 over Twelve Mile Creek 169 built?
It was built in 1947, making it 78 years old in 2025.
What condition is Old HWY 312 over Twelve Mile Creek 169 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 2024.
How much traffic does Old HWY 312 over Twelve Mile Creek 169 carry?
About 4,005 vehicles per day (2023 count), of which roughly 2% are trucks.
How long is Old HWY 312 over Twelve Mile Creek 169?
The structure is 101 ft (30.7 m) long with a longest span of 25 ft (7.7 m) and a deck 32 ft wide.
Who owns Old HWY 312 over Twelve Mile Creek 169?
It is owned by the State Highway Agency.