Bridge conditions in Clay County, Iowa
154 inventoried bridges · 16 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
Of the 154 Clay County bridges in the federal inventory, 16 carry a poor rating. That 10.4% share is roughly 2x the national average.
- 16 of the 154 bridges in Clay County, Iowa, are rated in poor condition (10.4%) in the 2025 National Bridge Inventory, as of .
- 58 bridges (37.7%) are rated good and 80 (51.9%) fair.
- The median Clay County bridge was built in 1989.
- The busiest poor-rated bridge is FM 340TH St over Little Sioux River (built 1963), carrying about 2,573 vehicles a day.
Good 37.7% · Fair 51.9% · Poor 10.4% of 154 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 |
|---|---|---|---|
| FM 340TH St over Little Sioux River | 1963 | 2,573 | Poor |
| FM 350TH St over Spring Creek | 1963 | 1,806 | Poor |
| FM 130TH Ave over Ocheyedan River | 1971 | 1,287 | Poor |
| FM 280TH Ave over Pickeral Run | 1993 | 459 | Poor |
| FM 480TH St over Little Sioux River | 1954 | 369 | Poor |
| FM 300TH St over Big Muddy Creek | 1963 | 369 | Poor |
| FM 280TH St over Little Sioux River | 1966 | 270 | Poor |
| FM 310TH Ave over Ditch NO.60 | 1967 | 259 | Poor |
| FM 160TH Ave over Willow Creek | 1962 | 190 | Poor |
| 210TH Ave over Little Sioux River | 1915 | 62 | Poor |
| 105TH Ave over Henry Creek | 1965 | 41 | Poor |
| 355TH St over Little Sioux River | 1905 | 41 | Poor |
| 110TH Ave over Willow Creek | 1928 | 30 | Poor |
| 470TH St over Little Sioux River | 1907 | 26 | Poor |
| 280TH Ave over Elk Creek | 1917 | 11 | Poor |
| 290TH St over Stream | 1913 | 5 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 18 & 71 over Little Sioux River | 2006 | 16,900 | Good |
| 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 |
| US 71 over Willow Creek | 1923 | 3,940 | Fair |
| US 18 over Ocheydon River Overflow | 1987 | 2,990 | Good |
| US 18 over Ocheyedan River | 2014 | 2,990 | Good |
Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.
All of Iowa: Iowa 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.