US Bridges

FM over Little Rock River

FairPosted for load

Lyon County, Iowa · 098441602 · Structure no. 000000000228330

Built
1950
75 years old
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
201 ft
3 main spans
Daily traffic
50
2022 count
Owner
County
County Highway Agency

About this bridge

FM over Little Rock River is a steel continuous stringer/multi-beam or girder carrying FM over Little Rock River in Lyon County, Iowa. It was built in 1950, so it is 75 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. Its operating status is: posted for load restriction.

It carries about 50 vehicles a day, projected to reach 50 by 2044. The structure is 201 ft (61.3 m) long and 22 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesFM
CrossesLittle Rock River
Location098441602
RouteCounty Highway 0
CountyLyon County
StateIowa
Coordinates43.30235, -96.05906
Functional classRural Minor Collector

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.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating30.2 US tons
Inventory rating18 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadUnknown
Structure length201 ft (61.3 m)
Longest span78 ft (23.8 m)
Deck width22 ft (6.7 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (2022)
Projected traffic50 by 2044
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was FM over Little Rock River built?

It was built in 1950, making it 75 years old in 2025.

What condition is FM over Little Rock 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 July 2024.

How much traffic does FM over Little Rock River carry?

About 50 vehicles per day (2022 count).

How long is FM over Little Rock River?

The structure is 201 ft (61.3 m) long with a longest span of 78 ft (23.8 m) and a deck 22 ft wide.

Who owns FM over Little Rock River?

It is owned by the County Highway Agency.