US Bridges

US 89 over Greenfields South Canal

Good

Teton County, Montana · 3M SE Fairfield · Structure no. P00003020+03001

Built
1983
42 years old
Condition
Good
inspected August 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
71 ft
1 main span
Daily traffic
1,798
2023 count
Owner
State
State Highway Agency

About this bridge

US 89 over Greenfields South Canal is a prestressed concrete stringer/multi-beam or girder carrying US 89 over Greenfields South Canal in Teton County, Montana. It was built in 1983, so it is 42 years old, younger than the Montana average of 47 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 1,798 vehicles a day, roughly 3% of them trucks, projected to reach 1,888 by 2043. The structure is 71 ft (21.6 m) long and 46 ft wide. If it were closed, the detour would be 5 mi (8 km).

CarriesUS 89
CrossesGreenfields South Canal
Location3M SE Fairfield
RouteU.S. Route 89
StateMontana
Coordinates47.59684, -111.93723
Functional classRural Minor Arterial

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating50 US tons
Inventory rating28 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length71 ft (21.6 m)
Longest span70 ft (21.3 m)
Deck width46 ft (14.1 m)
Roadway width43 ft (13.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,798 (2023)
Projected traffic1,888 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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 US 89 over Greenfields South Canal built?

It was built in 1983, making it 42 years old in 2025.

What condition is US 89 over Greenfields South Canal in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in August 2024.

How much traffic does US 89 over Greenfields South Canal carry?

About 1,798 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is US 89 over Greenfields South Canal?

The structure is 71 ft (21.6 m) long with a longest span of 70 ft (21.3 m) and a deck 46 ft wide.

Who owns US 89 over Greenfields South Canal?

It is owned by the State Highway Agency.