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US 18 & 71 over Little Sioux River

Clay County, Iowa · rated Good in the 2025 National Bridge Inventory

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

US 18 & 71 over Little Sioux River in Clay County, Iowa, is rated in good condition in the 2025 National Bridge Inventory (as of August 20, 2026).
Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
It was built in 2006, making it 19 years old at the 2025 inventory.
It carries about 16,900 vehicles a day (traffic count year 2022).
Its listed owner is the state highway agency.
It is one of 58 of the 154 inventoried bridges in Clay County rated good (37.7%); 16 (10.4%) are rated poor.
A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.

Component ratings


Structure	Prestressed concrete stringer or multi-beam girder
Length	about 458 ft
Location	0.7 mi. W of E jct. US 71
NBI structure number	000000000020331
Condition class	Good

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

Bridge	Built	Vehicles/day	Condition
US 71 over Br of Little Meadow Crk	1990	11,400	Fair
US 71 over Prairie Creek	2017	4,770	Good
US 18 over Lost Island Outlet	1931	4,270	Fair
US 18 over Drainage Ditch	1965	4,270	Fair
US 18 over Little Sioux River	2010	4,170	Good
US 18 over Little Sioux Overflow	1931	4,170	Fair