US Bridges

Blankenship RD over Flathead River 070

Fair

Flathead County, Montana · 4M NW Coram · Structure no. L15427002+03001

Built
1960
65 years old, rebuilt 1991
Condition
Fair
inspected August 2024
Type
Girder and Floorbeam System
Steel
Length
390 ft
4 main spans
Daily traffic
548
2023 count
Owner
County
County Highway Agency

About this bridge

Blankenship RD over Flathead River 070 is a steel girder and floorbeam system carrying Blankenship RD over Flathead River 070 in Flathead County, Montana. It was built in 1960 and reconstructed in 1991, so it is 65 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 548 vehicles a day, roughly 3% of them trucks, projected to reach 586 by 2043. The structure is 390 ft (118.8 m) long and 22 ft wide. If it were closed, the detour would be 19.9 mi (32 km).

Location

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CarriesBlankenship RD
CrossesFlathead River 070
Location4M NW Coram
RouteCounty Highway 15427
CountyFlathead County
StateMontana
Coordinates48.46545, -114.07166
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating45.3 US tons
Inventory rating33.5 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel
DeckConcrete, precast panels
Main spans4
Design loadUnknown
Structure length390 ft (118.8 m)
Longest span95 ft (29 m)
Deck width22 ft (6.6 m)
Roadway width18 ft (5.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic548 (2023)
Projected traffic586 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed19.9 mi (32 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$758,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Blankenship RD over Flathead River 070 built?

It was built in 1960, making it 65 years old in 2025. It was reconstructed in 1991.

What condition is Blankenship RD over Flathead River 070 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 2024.

How much traffic does Blankenship RD over Flathead River 070 carry?

About 548 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Blankenship RD over Flathead River 070?

The structure is 390 ft (118.8 m) long with a longest span of 95 ft (29 m) and a deck 22 ft wide.

Who owns Blankenship RD over Flathead River 070?

It is owned by the County Highway Agency.