Irr Bia Rte 4 over Birney Creek

Rosebud County, Montana · rated Good in the 2025 National Bridge Inventory

United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled August 20, 2026

• Irr Bia Rte 4 over Birney Creek in Rosebud County, Montana, is rated in good condition in the 2025 National Bridge Inventory (as of August 20, 2026).
• Its lowest-rated component is the culvert, rated 7 (good condition) on the 0-9 scale.
• It was built in 2007, making it 18 years old at the 2025 inventory.
• It carries about 250 vehicles a day (traffic count year 2024).
• It is one of 18 of the 112 inventoried bridges in Rosebud County rated good (16.1%); 7 (6.2%) 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 June 2024, on a 24-month routine inspection cycle.
• A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.

View this bridge on a map → (45.43432, -106.48501)

Component ratings

Bridge details

Source: FHWA National Bridge Inventory, 2025 data as reported by the Montana department of transportation.

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