US Bridges

Polebridge Road over North Fork Flathead Rive

Fair

Flathead County, Montana · 2 Miles North of U.S. Rou · Structure no. 1430024P0000000

Built
1991
34 years old
Condition
Fair
inspected September 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
360 ft
2 main spans
Daily traffic
100
2017 count
Owner
Federal
National Park Service

About this bridge

Polebridge Road over North Fork Flathead Rive is a steel continuous stringer/multi-beam or girder carrying Polebridge Road over North Fork Flathead Rive in Flathead County, Montana. It was built in 1991, so it is 34 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 1% of them trucks, projected to reach 200 by 2037. The structure is 360 ft (109.7 m) long and 26 ft wide. If it were closed, the detour would be 28 mi (45 km).

Location

Open in Google Maps
CarriesPolebridge Road
CrossesNorth Fork Flathead Rive
Location2 Miles North of U.S. Rou
RouteFederal Lands Road 15273
CountyFlathead County
StateMontana
Coordinates48.78306, -114.28122
Functional classRural Minor 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.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
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 rating57 US tons
Inventory rating34 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length360 ft (109.7 m)
Longest span180 ft (54.9 m)
Deck width26 ft (8 m)
Roadway width25 ft (7.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic100 (2017)
Projected traffic200 by 2037
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed28 mi (45 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerNational Park Service
Maintained byNational Park Service
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$173,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Polebridge Road over North Fork Flathead Rive built?

It was built in 1991, making it 34 years old in 2025.

What condition is Polebridge Road over North Fork Flathead Rive 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 September 2023.

How much traffic does Polebridge Road over North Fork Flathead Rive carry?

About 100 vehicles per day (2017 count), of which roughly 1% are trucks.

How long is Polebridge Road over North Fork Flathead Rive?

The structure is 360 ft (109.7 m) long with a longest span of 180 ft (54.9 m) and a deck 26 ft wide.

Who owns Polebridge Road over North Fork Flathead Rive?

It is owned by the National Park Service.