US 34 Ml over Big Thompson River
FairLarimer County, Colorado · 14 MI E of Estes Park · Structure no. C-15-C
- Built
- 1936
- 89 years old, rebuilt 1997
- Condition
- Fair
- inspected September 2023
- Type
- Stringer/Multi-beam or Girder
- Steel
- Length
- 110 ft
- 2 main spans
- Daily traffic
- 4,900
- 2020 count
- Owner
- State
- State Highway Agency
About this bridge
US 34 Ml over Big Thompson River is a steel stringer/multi-beam or girder carrying US 34 Ml over Big Thompson River in Larimer County, Colorado. It was built in 1936 and reconstructed in 1997, so it is 89 years old, older than the Colorado average of 42.2 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 4,900 vehicles a day, roughly 4% of them trucks, projected to reach 5,684 by 2040. The structure is 110 ft (33.5 m) long and 33 ft wide. If it were closed, the detour would be 24.2 mi (39 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 US 34 Ml over Big Thompson River built?
It was built in 1936, making it 89 years old in 2025. It was reconstructed in 1997.
What condition is US 34 Ml over Big Thompson 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 2023.
How much traffic does US 34 Ml over Big Thompson River carry?
About 4,900 vehicles per day (2020 count), of which roughly 4% are trucks.
How long is US 34 Ml over Big Thompson River?
The structure is 110 ft (33.5 m) long with a longest span of 52 ft (16 m) and a deck 33 ft wide.
Who owns US 34 Ml over Big Thompson River?
It is owned by the State Highway Agency.