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Bridge conditions in Deer Lodge County, Montana

67 inventoried bridges · 3 rated poor · 2025 National Bridge Inventory

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

The federal inventory lists 67 bridges in Deer Lodge County: 26 rated good, 38 fair, and 3 poor.

3 of the 67 bridges in Deer Lodge County, Montana, are rated in poor condition (4.5%) in the 2025 National Bridge Inventory, as of August 20, 2026.
26 bridges (38.8%) are rated good and 38 (56.7%) fair.
The median Deer Lodge County bridge was built in 1978.
The busiest poor-rated bridge is County Road 098 over Clark Fork River 020 (built 1920), carrying about 100 vehicles a day.

Good 38.8% · Fair 56.7% · Poor 4.5% of 67 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.

Bridge	Built	Vehicles/day	Condition
County Road 098 over Clark Fork River 020	1920	100	Poor
Mt Evans Way over Warm Springs Creek 016	1912	100	Poor
No Data Entered over E Fk Fishtrap	1973	20	Poor

Busiest bridges in the county

Bridge	Built	Vehicles/day	Condition
I 90 over Lost Creek	1978	11,628	Fair
I 90 over Willow Creek	1978	10,417	Fair
I 90 over Int Galen	1978	5,814	Fair
I 90 over Int Galen	1978	5,814	Good
I 90 over Sep Perkins Lane	1978	5,814	Fair
I 90 over Sep Huffman Lane	1978	5,814	Fair
I 90 over Int Warm Springs	1978	5,209	Good
I 90 over Int Warm Springs	1978	5,209	Good
I 90 over Clark Fork River	1978	5,209	Good
I 90 over Clark Fork River	1978	5,209	Good

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.