Stc 3809;MIDDLE Fk over M.fk.boise River(kirby)

Elmore County, Idaho · rated Poor in the 2025 National Bridge Inventory

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

• Stc 3809;MIDDLE Fk over M.fk.boise River(kirby) in Elmore County, Idaho, is rated in poor condition in the 2025 National Bridge Inventory (as of August 20, 2026).
• Its lowest-rated component is the superstructure, rated 4 (poor condition) on the 0-9 scale.
• It was built in 1991, making it 34 years old at the 2025 inventory.
• It carries about 30 vehicles a day (traffic count year 2023).
• It is one of 8 of the 98 inventoried bridges in Elmore County rated poor (8.2%); 8 (8.2%) are rated poor.
• Its traffic status in the 2025 inventory is posted for load (NBI item 41).
• It was rated fair in the 2024 inventory and is now poor (superstructure 6 to 4).
• Its most recent inspection on record is dated September 2024, on a 12-month routine inspection cycle.
• A poor rating means at least one major component - deck, superstructure, or substructure - is rated 4 or lower on FHWA's 0-9 scale. It does not by itself mean the bridge is unsafe; bridges judged unsafe are closed or load-restricted by their owners.

View this bridge on a map → (43.80283, -115.16253)

Component ratings

Bridge details

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

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Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.