County Road 21 over Culebra Creek
Costilla County, Colorado · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- County Road 21 over Culebra Creek in Costilla County, Colorado, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 1955, making it 70 years old at the 2025 inventory.
- It carries about 475 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 34 of the 38 inventoried bridges in Costilla County rated fair (89.5%); 0 (0.0%) 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: deck 6 to 7, superstructure 5 to 6, substructure 5 to 6.
- Its most recent inspection on record is dated March 2025, 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 → (37.15157, -105.39891)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 7 | Good condition |
| Superstructure | 5 | 6 | Satisfactory condition |
| Substructure | 5 | 6 | Satisfactory condition |
Bridge details
| Structure | Concrete tee beam |
| Length | about 94 ft |
| Location | Just SE OF CR L.7 |
| NBI structure number | CS242-S0.4-SMME |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | March 2025 |
| 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 Costilla County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 160 Ml over Canal | 1970 | 5,000 | Good |
| County Road P.6 over Unnamed Drainage | 2006 | 1,230 | Fair |
| SH 159 Ml over Culebra Creek | 1936 | 800 | Fair |
| C.rd Trinchera over Sangre De Cristo Creek | 1989 | 531 | Fair |
| SH 142 Ml over Rito Seco Creek | 1936 | 440 | Good |
| County Road P over Culebra Eastdale Canal | 1992 | 374 | Fair |
All bridges nearby: Costilla County, CO bridge conditions · every bridge in Costilla County · Colorado bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.