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Bridge conditions in Teton County, Montana

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

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

The federal inventory lists 82 bridges in Teton County: 34 rated good, 45 fair, and 3 poor.

3 of the 82 bridges in Teton County, Montana, are rated in poor condition (3.7%) in the 2025 National Bridge Inventory, as of August 20, 2026.
34 bridges (41.5%) are rated good and 45 (54.9%) fair.
The median Teton County bridge was built in 1976.
The busiest poor-rated bridge is 3RD Ln NW over Muddy Creek 018 (built 1938), carrying about 100 vehicles a day.

Good 41.5% · Fair 54.9% · Poor 3.7% of 82 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
3RD Ln NW over Muddy Creek 018	1938	100	Poor
8TH Ln NE over Greenfield So Canal 039	1966	100	Poor
6TH Ln NE over Drainage 129	1974	100	Poor

Busiest bridges in the county

Bridge	Built	Vehicles/day	Condition
I 15 over Sep 9TH Rd NE	1972	1,969	Good
I 15 over Sep 9TH Rd NE	1972	1,969	Good
US 89 over Greenfields South Canal	1983	1,798	Good
US 89 over Greenfields Main Canal	1983	1,798	Good
I 15 over Int Main St	1976	1,703	Fair
I 15 over Int Main St	1976	1,703	Fair
I 15 over Teton River	1977	1,703	Fair
I 15 over Teton River	1977	1,703	Good
US 89 over Teton River	1939	1,265	Fair
US 89 over Foster Creek	2018	654	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.