US Bridges

Central Ave E over Missouri River

Fair

Cascade County, Montana · Cascade · Structure no. S00330036+06001

Built
1954
71 years old
Condition
Fair
inspected April 2024
Type
Girder and Floorbeam System
Steel Continuous
Length
653 ft
4 main spans
Daily traffic
289
2023 count
Owner
State
State Highway Agency

About this bridge

Central Ave E over Missouri River is a steel continuous girder and floorbeam system carrying Central Ave E over Missouri River in Cascade County, Montana. It was built in 1954, so it is 71 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 289 vehicles a day, roughly 3% of them trucks, projected to reach 303 by 2043. The structure is 653 ft (199 m) long and 29 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

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CarriesCentral Ave E
CrossesMissouri River
LocationCascade
RouteState Highway 330
CountyCascade County
StateMontana
Coordinates47.26961, -111.69609
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating42 US tons
Inventory rating25 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 15
Structure length653 ft (199 m)
Longest span180 ft (54.9 m)
Deck width29 ft (8.9 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic289 (2023)
Projected traffic303 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 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 Central Ave E over Missouri River built?

It was built in 1954, making it 71 years old in 2025.

What condition is Central Ave E over Missouri 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 April 2024.

How much traffic does Central Ave E over Missouri River carry?

About 289 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Central Ave E over Missouri River?

The structure is 653 ft (199 m) long with a longest span of 180 ft (54.9 m) and a deck 29 ft wide.

Who owns Central Ave E over Missouri River?

It is owned by the State Highway Agency.