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Tr 339 over Mount Branch

Clark County, Illinois · rated Fair in the 2025 National Bridge Inventory

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

Tr 339 over Mount Branch in Clark County, Illinois, 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 1979, making it 46 years old at the 2025 inventory.
It carries about 200 vehicles a day (traffic count year 2021).
Its listed owner is a town or township highway agency.
It is one of 79 of the 231 inventoried bridges in Clark County rated fair (34.2%); 9 (3.9%) 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 multiple box beam
Length	about 40 ft
Location	2.0 Mi NW Moriah
NBI structure number	012321000000000
Condition class	Fair

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

Bridge	Built	Vehicles/day	Condition
I-70 over E Mill Creek Trib	1969	23,400	Fair
I-70 over E Mill Creek	1969	23,400	Fair
I-70 over E Mill Creek	1969	23,400	Fair
I-70 over Kettering Branch	1968	23,400	Fair
Fai 70 over Ditch	1971	23,400	Fair
I-70 over Stream	1968	22,800	Good