US 36 Ml over Canyon Creek
Boulder County, Colorado · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- US 36 Ml over Canyon Creek in Boulder County, Colorado, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1951, making it 74 years old at the 2025 inventory.
- It carries about 45,000 vehicles a day (traffic count year 2020).
- Its listed owner is the state highway agency.
- It is one of 211 of the 321 inventoried bridges in Boulder County rated fair (65.7%); 7 (2.2%) are rated poor.
- A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.
View this bridge on a map → (39.99451, -105.24899)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Culvert | 5 | Fair condition |
Bridge details
| Structure | Concrete culvert |
| Length | about 33 ft |
| Location | In Boulder |
| NBI structure number | E-15-AC |
| Condition class | Fair |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Colorado department of transportation.
Busiest bridges in Boulder County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 36 Ml over South Boulder Creek | 1951 | 77,000 | Good |
| US 36 Ml over Davidson Ditch | 2015 | 77,000 | Good |
| US 36 Ml over Coal Creek | 2015 | 66,000 | Good |
| Table Mesa Drive over US 36 Ml | 1951 | 44,000 | Fair |
| SH 157 Ramp over US 36 Ml | 1971 | 44,000 | Fair |
| SH 157 Ml over Skunk Creek | 1978 | 43,000 | Fair |
All bridges nearby: Boulder County, CO bridge conditions · every bridge in Boulder County · Colorado bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.