US Bridges

309 Avenue over Okobojo Ck

Fair

Sully County, South Dakota · 5E & 0.3N Agar · Structure no. 000000060360038

Built
1967
58 years old
Condition
Fair
inspected August 2023
Type
Channel Beam
Concrete
Length
31 ft
1 main span
Daily traffic
20
2022 count
Owner
County
County Highway Agency

About this bridge

309 Avenue over Okobojo Ck is a concrete channel beam carrying 309 Avenue over Okobojo Ck in Sully County, South Dakota. It was built in 1967, so it is 58 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 20 vehicles a day, roughly 2% of them trucks, projected to reach 20 by 2032. The structure is 31 ft (9.4 m) long and 32 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

Open in Google Maps
Carries309 Avenue
CrossesOkobojo Ck
Location5E & 0.3N Agar
RouteCounty Highway 0
CountySully County
StateSouth Dakota
Coordinates44.84243, -99.98016
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
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 inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry7: Better than present minimum criteria
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment7: Better than present minimum criteria
Operating rating36 US tons
Inventory rating27 US tons

Structure

Structure typeChannel Beam
MaterialConcrete
DeckConcrete, precast panels
Main spans1
Design loadUnknown
Structure length31 ft (9.4 m)
Longest span29 ft (8.8 m)
Deck width32 ft (9.7 m)
Roadway width30 ft (9.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic20 (2022)
Projected traffic20 by 2032
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 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$5,000
NavigationNo navigation control on waterway

Frequently asked questions

When was 309 Avenue over Okobojo Ck built?

It was built in 1967, making it 58 years old in 2025.

What condition is 309 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 August 2023.

How much traffic does 309 Avenue over Okobojo Ck carry?

About 20 vehicles per day (2022 count), of which roughly 2% are trucks.

How long is 309 Avenue over Okobojo Ck?

The structure is 31 ft (9.4 m) long with a longest span of 29 ft (8.8 m) and a deck 32 ft wide.

Who owns 309 Avenue over Okobojo Ck?

It is owned by the County Highway Agency.