US Bridges

North Fork RD over Whale Creek 048

Fair

Flathead County, Montana · 8M NW Polebridge · Structure no. L15175020+09001

Built
1976
49 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
145 ft
2 main spans
Daily traffic
73
2023 count
Owner
County
County Highway Agency

About this bridge

North Fork RD over Whale Creek 048 is a prestressed concrete stringer/multi-beam or girder carrying North Fork RD over Whale Creek 048 in Flathead County, Montana. It was built in 1976, so it is 49 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 5 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 73 vehicles a day, roughly 3% of them trucks, projected to reach 78 by 2043. The structure is 145 ft (44.2 m) long and 31 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

CarriesNorth Fork RD
CrossesWhale Creek 048
Location8M NW Polebridge
RouteCounty Highway 15175
StateMontana
Coordinates48.85133, -114.36269
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.
Superstructure8 Very GoodNo problems noted.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 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 geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating37 US tons
Inventory rating28 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length145 ft (44.2 m)
Longest span71 ft (21.6 m)
Deck width31 ft (9.4 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic73 (2023)
Projected traffic78 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

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 North Fork RD over Whale Creek 048 built?

It was built in 1976, making it 49 years old in 2025.

What condition is North Fork RD over Whale Creek 048 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 August 2023.

How much traffic does North Fork RD over Whale Creek 048 carry?

About 73 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is North Fork RD over Whale Creek 048?

The structure is 145 ft (44.2 m) long with a longest span of 71 ft (21.6 m) and a deck 31 ft wide.

Who owns North Fork RD over Whale Creek 048?

It is owned by the County Highway Agency.