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US 310 over Clarks Fk Yellowstone

Carbon County, Montana · rated Fair in the 2025 National Bridge Inventory

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

US 310 over Clarks Fk Yellowstone in Carbon County, Montana, is rated in fair condition in the 2025 National Bridge Inventory (as of August 20, 2026).
Its lowest-rated component is the deck, rated 6 (satisfactory condition) on the 0-9 scale.
It was built in 1971, making it 54 years old at the 2025 inventory.
It carries about 1,932 vehicles a day (traffic count year 2023).
Its listed owner is the state highway agency.
It is one of 46 of the 81 inventoried bridges in Carbon County rated fair (56.8%); 4 (4.9%) are rated poor.
A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.

Component ratings


Structure	Prestressed concrete stringer or multi-beam girder
Length	about 289 ft
Location	2M S Bridger
NBI structure number	P00004023+07461
Condition class	Fair

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

Bridge	Built	Vehicles/day	Condition
US 310 over Sand Creek	1987	4,907	Good
US 310 over Rock Creek	1934	4,561	Fair
US 212 over Rock Creek	1974	3,817	Fair
US 212 over Rock Creek	2001	2,491	Good
US 310 over Bridger Creek	1971	1,932	Fair
S 72 over Bear Creek	2013	1,732	Good