US Bridges

IRR - S 358 over Birch Creek

Fair

Pondera County, Montana · 7M NW Valier · Structure no. S00358007+04001

Built
1965
60 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
286 ft
4 main spans
Daily traffic
292
2023 count
Owner
State
State Highway Agency

About this bridge

IRR - S 358 over Birch Creek is a prestressed concrete stringer/multi-beam or girder carrying IRR - S 358 over Birch Creek in Pondera County, Montana. It was built in 1965, so it is 60 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 292 vehicles a day, roughly 8% of them trucks, projected to reach 307 by 2043. The structure is 286 ft (87.1 m) long and 36 ft wide. If it were closed, the detour would be 31.1 mi (50 km).

Location

Open in Google Maps
CarriesIRR - S 358
CrossesBirch Creek
Location7M NW Valier
RouteState Highway 358
CountyPondera County
StateMontana
Coordinates48.35734, -112.34262
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.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 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 geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating51 US tons
Inventory rating25 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadHS 15
Structure length286 ft (87.1 m)
Longest span72 ft (21.8 m)
Deck width36 ft (10.9 m)
Roadway width30 ft (9.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic292 (2023)
Projected traffic307 by 2043
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed31.1 mi (50 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 IRR - S 358 over Birch Creek built?

It was built in 1965, making it 60 years old in 2025.

What condition is IRR - S 358 over Birch 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 IRR - S 358 over Birch Creek carry?

About 292 vehicles per day (2023 count), of which roughly 8% are trucks.

How long is IRR - S 358 over Birch Creek?

The structure is 286 ft (87.1 m) long with a longest span of 72 ft (21.8 m) and a deck 36 ft wide.

Who owns IRR - S 358 over Birch Creek?

It is owned by the State Highway Agency.