US Bridges

S 359 over Jefferson River

Fair

Madison County, Montana · Jefferson Island · Structure no. S00359002+02661

Built
1967
58 years old
Condition
Fair
inspected October 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
289 ft
3 main spans
Daily traffic
1,429
2023 count
Owner
State
State Highway Agency

About this bridge

S 359 over Jefferson River is a prestressed concrete stringer/multi-beam or girder carrying S 359 over Jefferson River in Madison County, Montana. It was built in 1967, so it is 58 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 1,429 vehicles a day, roughly 5% of them trucks, projected to reach 1,579 by 2043. The structure is 289 ft (88.1 m) long and 33 ft wide. If it were closed, the detour would be 46 mi (74 km).

Location

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CarriesS 359
CrossesJefferson River
LocationJefferson Island
RouteState Highway 359
CountyMadison County
StateMontana
Coordinates45.85482, -111.95077
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating53 US tons
Inventory rating28 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 15
Structure length289 ft (88.1 m)
Longest span97 ft (29.6 m)
Deck width33 ft (10.1 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,429 (2023)
Projected traffic1,579 by 2043
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed46 mi (74 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 359 over Jefferson River built?

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

What condition is S 359 over Jefferson River 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 October 2023.

How much traffic does S 359 over Jefferson River carry?

About 1,429 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is S 359 over Jefferson River?

The structure is 289 ft (88.1 m) long with a longest span of 97 ft (29.6 m) and a deck 33 ft wide.

Who owns S 359 over Jefferson River?

It is owned by the State Highway Agency.