US Bridges

S 2 over Jefferson River

Fair

Gallatin County, Montana · 2M W Three Forks · Structure no. P00013093+06931

Built
1949
76 years old
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
247 ft
3 main spans
Daily traffic
1,515
2023 count
Owner
State
State Highway Agency

About this bridge

S 2 over Jefferson River is a steel continuous stringer/multi-beam or girder carrying S 2 over Jefferson River in Gallatin County, Montana. It was built in 1949, so it is 76 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 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 1,515 vehicles a day, roughly 5% of them trucks, projected to reach 1,659 by 2043. The structure is 247 ft (75.3 m) long and 32 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

Open in Google Maps
CarriesS 2
CrossesJefferson River
Location2M W Three Forks
RouteState Highway 2
CountyGallatin County
StateMontana
Coordinates45.89693, -111.59628
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
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 inspectionMay 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 adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating56 US tons
Inventory rating43 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length247 ft (75.3 m)
Longest span95 ft (29 m)
Deck width32 ft (9.9 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,515 (2023)
Projected traffic1,659 by 2043
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed9.9 mi (16 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 2 over Jefferson River built?

It was built in 1949, making it 76 years old in 2025.

What condition is S 2 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 May 2023.

How much traffic does S 2 over Jefferson River carry?

About 1,515 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is S 2 over Jefferson River?

The structure is 247 ft (75.3 m) long with a longest span of 95 ft (29 m) and a deck 32 ft wide.

Who owns S 2 over Jefferson River?

It is owned by the State Highway Agency.