US Bridges

S 323 over Box Elder Creek

Fair

Carter County, Montana · 17M SE Ekalaka · Structure no. S00323017+07001

Built
1957
68 years old
Condition
Fair
inspected August 2023
Type
Tee Beam
Concrete
Length
184 ft
3 main spans
Daily traffic
316
2023 count
Owner
State
State Highway Agency

About this bridge

S 323 over Box Elder Creek is a concrete tee beam carrying S 323 over Box Elder Creek in Carter County, Montana. It was built in 1957, so it is 68 years old, older than the Montana average of 47 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.

It carries about 316 vehicles a day, roughly 13% of them trucks, projected to reach 332 by 2043. The structure is 184 ft (56 m) long and 27 ft wide. If it were closed, the detour would be 19.9 mi (32 km).

Location

Open in Google Maps
CarriesS 323
CrossesBox Elder Creek
Location17M SE Ekalaka
RouteState Highway 323
CountyCarter County
StateMontana
Coordinates45.68778, -104.36925
Functional classRural Minor Arterial

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
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 adequacy4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating28 US tons
Inventory rating19 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 15
Structure length184 ft (56 m)
Longest span63 ft (19.2 m)
Deck width27 ft (8.1 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic316 (2023)
Projected traffic332 by 2043
Trucks13%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed19.9 mi (32 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 S 323 over Box Elder Creek built?

It was built in 1957, making it 68 years old in 2025.

What condition is S 323 over Box Elder 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 August 2023.

How much traffic does S 323 over Box Elder Creek carry?

About 316 vehicles per day (2023 count), of which roughly 13% are trucks.

How long is S 323 over Box Elder Creek?

The structure is 184 ft (56 m) long with a longest span of 63 ft (19.2 m) and a deck 27 ft wide.

Who owns S 323 over Box Elder Creek?

It is owned by the State Highway Agency.