US Bridges

N Reserve ST over Clark Fork R Flood Plain

Fair

Missoula County, Montana · Missoula-N Reserve ST · Structure no. U08103003+01631

Built
1977
48 years old
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
334 ft
3 main spans
Daily traffic
35,914
2023 count
Owner
State
State Highway Agency

About this bridge

N Reserve ST over Clark Fork R Flood Plain is a prestressed concrete stringer/multi-beam or girder carrying N Reserve ST over Clark Fork R Flood Plain in Missoula County, Montana. It was built in 1977, so it is 48 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 35,914 vehicles a day, roughly 1% of them trucks, projected to reach 37,710 by 2043. The structure is 334 ft (101.8 m) long and 79 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

CarriesN Reserve ST
CrossesClark Fork R Flood Plain
LocationMissoula-N Reserve ST
RouteU.S. Route 93
StateMontana
Coordinates46.87996, -114.03701
Functional classUrban Other Principal Arterial

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 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 geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating58 US tons
Inventory rating35.1 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length334 ft (101.8 m)
Longest span112 ft (34.1 m)
Deck width79 ft (24.2 m)
Roadway width61 ft (18.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic35,914 (2023)
Projected traffic37,710 by 2043
Trucks1%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemYes

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 N Reserve ST over Clark Fork R Flood Plain built?

It was built in 1977, making it 48 years old in 2025.

What condition is N Reserve ST over Clark Fork R Flood Plain 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 July 2024.

How much traffic does N Reserve ST over Clark Fork R Flood Plain carry?

About 35,914 vehicles per day (2023 count), of which roughly 1% are trucks.

How long is N Reserve ST over Clark Fork R Flood Plain?

The structure is 334 ft (101.8 m) long with a longest span of 112 ft (34.1 m) and a deck 79 ft wide.

Who owns N Reserve ST over Clark Fork R Flood Plain?

It is owned by the State Highway Agency.