Roaring River Road over Middle Fork Boise River

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

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

• Roaring River Road over Middle Fork Boise River 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 substructure, rated 2 (critical condition) on the 0-9 scale.
• It was built in 1957, making it 68 years old at the 2025 inventory.
• It carries about 20 vehicles a day (traffic count year 1992).
• 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 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 September 2023, on a 12-month routine inspection cycle.
• It is coded scour critical (NBI item 113 = 2): scour critical: extensive scour observed, foundations unstable.
• 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 → (43.79037, -115.43719)

Component ratings

Bridge details

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

Busiest bridges in Elmore County

All bridges nearby: Elmore County, ID bridge conditions · every bridge in Elmore County · Idaho bridges.

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