US Bridges

IRR County Road over Flint Rock Ck

FairPosted for load

Ziebach County, South Dakota · 5.5 N & 8.5 W Red El · Structure no. 000000069030234

Built
1945
80 years old
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
136 ft
5 main spans
Daily traffic
16
2022 count
Owner
County
County Highway Agency

About this bridge

IRR County Road over Flint Rock Ck is a steel stringer/multi-beam or girder carrying IRR County Road over Flint Rock Ck in Ziebach County, South Dakota. It was built in 1945, so it is 80 years old, older than the South Dakota average of 48.9 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 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 16 vehicles a day, roughly 2% of them trucks, projected to reach 16 by 2032. The structure is 136 ft (41.5 m) long and 22 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

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CarriesIRR County Road
CrossesFlint Rock Ck
Location5.5 N & 8.5 W Red El
RouteCounty Highway 0
CountyZiebach County
StateSouth Dakota
Coordinates45.13432, -101.95637
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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
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 adequacy8: Equal to present desirable criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating27 US tons
Inventory rating20.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans5
Design loadUnknown
Structure length136 ft (41.5 m)
Longest span30 ft (9.1 m)
Deck width22 ft (6.7 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic16 (2022)
Projected traffic16 by 2032
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 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 IRR County Road over Flint Rock Ck built?

It was built in 1945, making it 80 years old in 2025.

What condition is IRR County Road over Flint Rock Ck 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 IRR County Road over Flint Rock Ck carry?

About 16 vehicles per day (2022 count), of which roughly 2% are trucks.

How long is IRR County Road over Flint Rock Ck?

The structure is 136 ft (41.5 m) long with a longest span of 30 ft (9.1 m) and a deck 22 ft wide.

Who owns IRR County Road over Flint Rock Ck?

It is owned by the County Highway Agency.