US Bridges

350th ST over Little Sioux River

Fair

Clay County, Iowa · 096371405 · Structure no. 000000000116871

Built
1976
49 years old
Condition
Fair
inspected April 2023
Type
Slab
Concrete Continuous
Length
223 ft
5 main spans
Daily traffic
2,584
2022 count
Owner
County
County Highway Agency

About this bridge

350th ST over Little Sioux River is a concrete continuous slab carrying 350th ST over Little Sioux River in Clay County, Iowa. It was built in 1976, so it is 49 years old, older than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 2,584 vehicles a day, projected to reach 2,584 by 2043. The structure is 223 ft (68 m) long and 45 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
Carries350th ST
CrossesLittle Sioux River
Location096371405
RouteCounty Highway 0
CountyClay County
StateIowa
Coordinates43.14171, -95.1843
Functional classUrban Minor Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating69.3 US tons
Inventory rating41.4 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans5
Design loadH 20
Structure length223 ft (68 m)
Longest span49 ft (14.9 m)
Deck width45 ft (13.7 m)
Roadway width42 ft (12.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,584 (2022)
Projected traffic2,584 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was 350th ST over Little Sioux River built?

It was built in 1976, making it 49 years old in 2025.

What condition is 350th ST over Little Sioux River in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in April 2023.

How much traffic does 350th ST over Little Sioux River carry?

About 2,584 vehicles per day (2022 count).

How long is 350th ST over Little Sioux River?

The structure is 223 ft (68 m) long with a longest span of 49 ft (14.9 m) and a deck 45 ft wide.

Who owns 350th ST over Little Sioux River?

It is owned by the County Highway Agency.