Bridge conditions in Sierra County, New Mexico
112 inventoried bridges · 5 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
The federal inventory lists 112 bridges in Sierra County: 34 rated good, 73 fair, and 5 poor.
- 5 of the 112 bridges in Sierra County, New Mexico, are rated in poor condition (4.5%) in the 2025 National Bridge Inventory, as of .
- 34 bridges (30.4%) are rated good and 73 (65.2%) fair.
- The median Sierra County bridge was built in 1968.
- The busiest poor-rated bridge is I-25 Sbl/nbl over Unnamed Waterway (built 1965), carrying about 7,331 vehicles a day.
Good 30.4% · Fair 65.2% · Poor 4.5% of 112 bridges
Bridges rated poor
Every bridge in the county with a poor rating, busiest first. Poor means a major component is rated 4 or lower on FHWA's 0-9 scale; it is a repair flag, not a closure notice.
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-25 Sbl/nbl over Unnamed Waterway | 1965 | 7,331 | Poor |
| L-00011 over I-25 NB and SB | 1968 | 1,196 | Poor |
| Nm-187 over King Canyon | 1933 | 521 | Poor |
| Nm-187 over Greenhorn Arroyo | 1928 | 297 | Poor |
| 51-b038 over Rio Grande | 1966 | 70 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-25 Nbl over Palomas Creek | 1968 | 8,962 | Fair |
| I-25 Sbl over Palomas Creek | 1968 | 8,962 | Fair |
| I-25 Nbl/sbl over Canada Honda | 1968 | 8,962 | Fair |
| I-25 Nbl/sbl over County Rd-b079 | 1968 | 8,962 | Fair |
| I-25 NB over Nm-181 | 1967 | 8,510 | Fair |
| I-25 Nbl over Percha Creek | 1965 | 8,008 | Fair |
| I-25 Sbl over Percha Creek | 1965 | 8,008 | Fair |
| I-25 Nbl over Green Horn Arroyo | 1966 | 8,008 | Fair |
| I-25 Sbl over Green Horn Arroyo | 1966 | 8,008 | Fair |
| I-25 Nbl/sbl over Unnamed Waterway | 1966 | 8,008 | Fair |
Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.
All of New Mexico: New Mexico bridge conditions by county · every download on the data page.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.