County Road 129B over Mid Fk. Little Snake Rvr
Routt County, Colorado · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- County Road 129B over Mid Fk. Little Snake Rvr in Routt County, Colorado, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1985, making it 40 years old at the 2025 inventory.
- It carries about 23 vehicles a day (traffic count year 2023).
- Its listed owner is the county highway agency.
- It is one of 48 of the 97 inventoried bridges in Routt County rated fair (49.5%); 7 (7.2%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated October 2024, on a 24-month routine inspection cycle.
- It is coded scour critical (NBI item 113 = 3): scour critical: foundations unstable for the assessed or calculated scour.
- 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 → (40.99051, -107.04442)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 5 | 5 | Fair condition |
| Superstructure | 6 | 6 | Satisfactory condition |
| Substructure | 6 | 6 | Satisfactory condition |
Bridge details
| Structure | Steel stringer or multi-beam girder |
| Length | about 85 ft |
| Location | 0.3 Mi NE of Co Rd 129 |
| NBI structure number | 107129B00.30939 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | October 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 3: scour critical: foundations unstable for the assessed or calculated scour |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Colorado department of transportation.
Busiest bridges in Routt County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 40 Ml over Fish Creek | 1980 | 28,000 | Fair |
| US 40 Ml over Mt Werner Road | 1980 | 23,000 | Fair |
| US 40 Ml over Walton Creek | 1990 | 9,200 | Fair |
| US 40 Ml over Shelton Ditch | 1954 | 6,400 | Poor |
| Fish Crk Falls Rd over Spring Creek | 1973 | 5,949 | Fair |
| US 40 Ml over E Fork Elk River | 2013 | 5,700 | Good |
All bridges nearby: Routt County, CO bridge conditions · every bridge in Routt County · Colorado bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.