US Bridges

Waterloo RD over Jefferson River

Fair

Jefferson County, Montana · 9M NE Silverstar · Structure no. S00422008+02531

Built
1961
64 years old
Condition
Fair
inspected February 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
244 ft
4 main spans
Daily traffic
242
2023 count
Owner
County
County Highway Agency

About this bridge

Waterloo RD over Jefferson River is a prestressed concrete stringer/multi-beam or girder carrying Waterloo RD over Jefferson River in Jefferson County, Montana. It was built in 1961, so it is 64 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 242 vehicles a day, projected to reach 254 by 2043. The structure is 244 ft (74.5 m) long and 27 ft wide. If it were closed, the detour would be 16.2 mi (26 km).

Location

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CarriesWaterloo RD
CrossesJefferson River
Location9M NE Silverstar
RouteCounty Highway 422
CountyJefferson County
StateMontana
Coordinates45.74858, -112.1903
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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionFebruary 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 adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating51 US tons
Inventory rating30 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadHS 15
Structure length244 ft (74.5 m)
Longest span60 ft (18.3 m)
Deck width27 ft (8.2 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic242 (2023)
Projected traffic254 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed16.2 mi (26 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 Waterloo RD over Jefferson River built?

It was built in 1961, making it 64 years old in 2025.

What condition is Waterloo RD 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 February 2023.

How much traffic does Waterloo RD over Jefferson River carry?

About 242 vehicles per day (2023 count).

How long is Waterloo RD over Jefferson River?

The structure is 244 ft (74.5 m) long with a longest span of 60 ft (18.3 m) and a deck 27 ft wide.

Who owns Waterloo RD over Jefferson River?

It is owned by the County Highway Agency.