US 550 Ml over Animas River
La Plata County, Colorado · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- US 550 Ml over Animas River in La Plata County, Colorado, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1910 and reconstructed in 1965, making it 115 years old at the 2025 inventory.
- It carries about 28,000 vehicles a day (traffic count year 2020).
- Its listed owner is the state highway agency.
- It is one of 59 of the 105 inventoried bridges in La Plata County rated fair (56.2%); 1 (1.0%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its class is unchanged from 2024 (fair), but component ratings moved: substructure 5 to 6.
- Its most recent inspection on record is dated October 2023, on a 24-month routine inspection cycle.
- 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 → (37.28064, -107.87818)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 5 | 5 | Fair condition |
| Substructure | 5 | 6 | Satisfactory condition |
Bridge details
| Structure | Concrete deck arch |
| Length | about 150 ft |
| Location | In Durango |
| NBI structure number | O-05-J |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | October 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Colorado department of transportation.
Busiest bridges in La Plata County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 160 Ml over City St_animas Rvr | 1979 | 35,000 | Fair |
| US 160 Ml over Animas River | 1974 | 30,000 | Fair |
| US 160 Ml over Lightner Creek | 1970 | 19,000 | Fair |
| Private Land Acces over Lightner Creek Ar | 1973 | 19,000 | Fair |
| US 160 Ml over Animas River | 1968 | 17,000 | Fair |
| Three Springs Blvd over Traverse Wash | 2004 | 12,427 | Fair |
All bridges nearby: La Plata County, CO bridge conditions · every bridge in La Plata County · Colorado bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.