US Bridges

5th LN over Greenfield S Canal 045

Fair

Cascade County, Montana · 5M E Fairfield · Structure no. L07021000+01001

Built
2003
22 years old
Condition
Fair
inspected December 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
57 ft
2 main spans
Daily traffic
100
2025 count
Owner
County
County Highway Agency

About this bridge

5th LN over Greenfield S Canal 045 is a steel continuous stringer/multi-beam or girder carrying 5th LN over Greenfield S Canal 045 in Cascade County, Montana. It was built in 2003, so it is 22 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 100 vehicles a day, roughly 3% of them trucks, projected to reach 100 by 2040. The structure is 57 ft (17.4 m) long and 20 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
Carries5th LN
CrossesGreenfield S Canal 045
Location5M E Fairfield
RouteCounty Highway 7021
CountyCascade County
StateMontana
Coordinates47.59838, -111.88016
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionDecember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating31.1 US tons
Inventory rating18.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckCorrugated steel
Main spans2
Design loadHS 20
Structure length57 ft (17.4 m)
Longest span39 ft (11.9 m)
Deck width20 ft (6.2 m)
Roadway width20 ft (6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic100 (2025)
Projected traffic100 by 2040
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 5th LN over Greenfield S Canal 045 built?

It was built in 2003, making it 22 years old in 2025.

What condition is 5th LN over Greenfield S Canal 045 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 December 2023.

How much traffic does 5th LN over Greenfield S Canal 045 carry?

About 100 vehicles per day (2025 count), of which roughly 3% are trucks.

How long is 5th LN over Greenfield S Canal 045?

The structure is 57 ft (17.4 m) long with a longest span of 39 ft (11.9 m) and a deck 20 ft wide.

Who owns 5th LN over Greenfield S Canal 045?

It is owned by the County Highway Agency.