US Bridges

170th ST over Mink Creek

Fair

Plymouth County, Iowa · 092460903 · Structure no. 000000000274870

Built
1934
91 years old
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
150 ft
3 main spans
Daily traffic
60
2022 count
Owner
County
County Highway Agency

About this bridge

170th ST over Mink Creek is a steel continuous stringer/multi-beam or girder carrying 170th ST over Mink Creek in Plymouth County, Iowa. It was built in 1934, so it is 91 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 60 vehicles a day, projected to reach 60 by 2043. The structure is 150 ft (45.7 m) long and 27 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
Carries170th ST
CrossesMink Creek
Location092460903
RouteCounty Highway 0
CountyPlymouth County
StateIowa
Coordinates42.80781, -96.27569
Functional classRural Local

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 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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating47.8 US tons
Inventory rating28.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length150 ft (45.7 m)
Longest span59 ft (18 m)
Deck width27 ft (8.3 m)
Roadway width24 ft (7.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic60 (2022)
Projected traffic60 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 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 proposedNone recorded
Estimated improvement cost$750,000
NavigationNo navigation control on waterway

Frequently asked questions

When was 170th ST over Mink Creek built?

It was built in 1934, making it 91 years old in 2025.

What condition is 170th ST over Mink Creek 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 170th ST over Mink Creek carry?

About 60 vehicles per day (2022 count).

How long is 170th ST over Mink Creek?

The structure is 150 ft (45.7 m) long with a longest span of 59 ft (18 m) and a deck 27 ft wide.

Who owns 170th ST over Mink Creek?

It is owned by the County Highway Agency.