US Bridges

291 Avenue over Okobojo Ck

Fair

Sully County, South Dakota · 3.5E & 0.6N Okobojo · Structure no. 000000060190165

Built
1936
89 years old
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
98 ft
3 main spans
Daily traffic
250
2022 count
Owner
County
County Highway Agency

About this bridge

291 Avenue over Okobojo Ck is a steel stringer/multi-beam or girder carrying 291 Avenue over Okobojo Ck in Sully County, South Dakota. It was built in 1936, so it is 89 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 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 250 vehicles a day, roughly 3% of them trucks, projected to reach 250 by 2032. The structure is 98 ft (29.9 m) long and 27 ft wide. If it were closed, the detour would be 16.8 mi (27 km).

Location

Open in Google Maps
Carries291 Avenue
CrossesOkobojo Ck
Location3.5E & 0.6N Okobojo
RouteCounty Highway 0
CountySully County
StateSouth Dakota
Coordinates44.65704, -100.32448
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 protection8 Very GoodNo problems noted.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
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 alignment8: Equal to present desirable criteria
Operating rating47.3 US tons
Inventory rating28.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans3
Design loadHL 93
Structure length98 ft (29.9 m)
Longest span32 ft (9.8 m)
Deck width27 ft (8.3 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic250 (2022)
Projected traffic250 by 2032
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed16.8 mi (27 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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$16,000
NavigationNo navigation control on waterway

Frequently asked questions

When was 291 Avenue over Okobojo Ck built?

It was built in 1936, making it 89 years old in 2025.

What condition is 291 Avenue over Okobojo 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 2023.

How much traffic does 291 Avenue over Okobojo Ck carry?

About 250 vehicles per day (2022 count), of which roughly 3% are trucks.

How long is 291 Avenue over Okobojo Ck?

The structure is 98 ft (29.9 m) long with a longest span of 32 ft (9.8 m) and a deck 27 ft wide.

Who owns 291 Avenue over Okobojo Ck?

It is owned by the County Highway Agency.