US Bridges

FM over South Skunk River

Fair

Keokuk County, Iowa · 074100604 · Structure no. 000000000209410

Built
1969
56 years old
Condition
Fair
inspected March 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
545 ft
6 main spans
Daily traffic
220
2022 count
Owner
County
County Highway Agency

About this bridge

FM over South Skunk River is a steel continuous stringer/multi-beam or girder carrying FM over South Skunk River in Keokuk County, Iowa. It was built in 1969, so it is 56 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 220 vehicles a day, roughly 30% of them trucks, projected to reach 220 by 2044. The structure is 545 ft (166.1 m) long and 26 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

Open in Google Maps
CarriesFM
CrossesSouth Skunk River
Location074100604
RouteCounty Highway 0
CountyKeokuk County
StateIowa
Coordinates41.24089, -92.06375
Functional classRural Major 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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 2024
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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating41.6 US tons
Inventory rating24.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans6
Design loadH 15
Structure length545 ft (166.1 m)
Longest span97 ft (29.6 m)
Deck width26 ft (7.9 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic220 (2022)
Projected traffic220 by 2044
Trucks30%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed9.9 mi (16 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$7 million (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was FM over South Skunk River built?

It was built in 1969, making it 56 years old in 2025.

What condition is FM over South Skunk 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 March 2024.

How much traffic does FM over South Skunk River carry?

About 220 vehicles per day (2022 count), of which roughly 30% are trucks.

How long is FM over South Skunk River?

The structure is 545 ft (166.1 m) long with a longest span of 97 ft (29.6 m) and a deck 26 ft wide.

Who owns FM over South Skunk River?

It is owned by the County Highway Agency.