US Bridges

Csah 12 over Upper Iowa River

Fair

Mower County, Minnesota · 0.7 MI N of JCT TH 56 · Structure no. 50540

Built
1977
48 years old
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
158 ft
3 main spans
Daily traffic
875
2012 count
Owner
County
County Highway Agency

About this bridge

Csah 12 over Upper Iowa River is a steel continuous stringer/multi-beam or girder carrying Csah 12 over Upper Iowa River in Mower County, Minnesota. It was built in 1977, so it is 48 years old, older than the Minnesota average of 38.5 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 875 vehicles a day, projected to reach 875 by 2039. The structure is 158 ft (48.3 m) long and 40 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesCsah 12
CrossesUpper Iowa River
Location0.7 MI N of JCT TH 56
RouteCounty Highway 12
CountyMower County
StateMinnesota
Coordinates43.51871, -92.50007
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 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 geometry7: Better than present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating67 US tons
Inventory rating40.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length158 ft (48.3 m)
Longest span60 ft (18.3 m)
Deck width40 ft (12.1 m)
Roadway width36 ft (11 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic875 (2012)
Projected traffic875 by 2039
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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 Csah 12 over Upper Iowa River built?

It was built in 1977, making it 48 years old in 2025.

What condition is Csah 12 over Upper Iowa 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 2023.

How much traffic does Csah 12 over Upper Iowa River carry?

About 875 vehicles per day (2012 count).

How long is Csah 12 over Upper Iowa River?

The structure is 158 ft (48.3 m) long with a longest span of 60 ft (18.3 m) and a deck 40 ft wide.

Who owns Csah 12 over Upper Iowa River?

It is owned by the County Highway Agency.