Bridge conditions in Prairie County, Montana

46 inventoried bridges · 5 rated poor · 2025 National Bridge Inventory

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

About one in 9 bridges in Prairie County is rated in poor condition: 5 of 46 on the federal inventory, one of the higher shares in Montana.

• 5 of the 46 bridges in Prairie County, Montana, are rated in poor condition (10.9%) in the 2025 National Bridge Inventory, as of August 20, 2026.
• 4 bridges (8.7%) are rated good and 37 (80.4%) fair.
• The median Prairie County bridge was built in 1969.
• The busiest poor-rated bridge is Old Hwy 10 W over Williams Coulee 007 (built 1930), carrying about 507 vehicles a day.

Good 8.7% · Fair 80.4% · Poor 10.9% of 46 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.

Busiest bridges in the county

Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.

All of Montana: Montana 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.