US 36 Ml over Supply Ditch
FairBoulder County, Colorado · In Lyons · Structure no. D-15-BE
- Built
- 1972
- 53 years old
- Condition
- Fair
- inspected March 2025
- Type
- Culvert
- Concrete
- Length
- 23 ft
- 2 main spans
- Daily traffic
- 15,000
- 2020 count
- Owner
- State
- State Highway Agency
About this bridge
US 36 Ml over Supply Ditch is a concrete culvert carrying US 36 Ml over Supply Ditch in Boulder County, Colorado. It was built in 1972, so it is 53 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 15,000 vehicles a day, roughly 3% of them trucks, projected to reach 18,900 by 2040. The structure is 23 ft (6.9 m) long and 91 ft wide. If it were closed, the detour would be 29.8 mi (48 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 |
|---|---|---|
| Channel and channel protection | 7 Good | Some minor problems. |
| Culvert | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was US 36 Ml over Supply Ditch built?
It was built in 1972, making it 53 years old in 2025.
What condition is US 36 Ml over Supply Ditch 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 March 2025.
How much traffic does US 36 Ml over Supply Ditch carry?
About 15,000 vehicles per day (2020 count), of which roughly 3% are trucks.
How long is US 36 Ml over Supply Ditch?
The structure is 23 ft (6.9 m) long with a longest span of 11 ft (3.3 m) and a deck 91 ft wide.
Who owns US 36 Ml over Supply Ditch?
It is owned by the State Highway Agency.