US Bridges

S 200 over Sun River

Fair

Cascade County, Montana · Sun River · Structure no. P00024138+05111

Built
1996
29 years old
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
266 ft
3 main spans
Daily traffic
2,505
2023 count
Owner
State
State Highway Agency

About this bridge

S 200 over Sun River is a steel continuous stringer/multi-beam or girder carrying S 200 over Sun River in Cascade County, Montana. It was built in 1996, so it is 29 years old, younger 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 2,505 vehicles a day, roughly 7% of them trucks, projected to reach 2,630 by 2043. The structure is 266 ft (81.1 m) long and 48 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesS 200
CrossesSun River
LocationSun River
RouteState Highway 200
CountyCascade County
StateMontana
Coordinates47.53528, -111.71775
Functional classRural Principal Arterial - Other

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 inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating49.1 US tons
Inventory rating37 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length266 ft (81.1 m)
Longest span100 ft (30.5 m)
Deck width48 ft (14.7 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,505 (2023)
Projected traffic2,630 by 2043
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemYes

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 200 over Sun River built?

It was built in 1996, making it 29 years old in 2025.

What condition is S 200 over Sun 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 July 2023.

How much traffic does S 200 over Sun River carry?

About 2,505 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is S 200 over Sun River?

The structure is 266 ft (81.1 m) long with a longest span of 100 ft (30.5 m) and a deck 48 ft wide.

Who owns S 200 over Sun River?

It is owned by the State Highway Agency.