US Bridges

Arlene RD over Clark Fork 105

Fair

Missoula County, Montana · 24M SE Missoula · Structure no. L32218001+05001

Built
1976
49 years old
Condition
Fair
inspected November 2023
Type
Tee Beam
Prestressed Concrete
Length
134 ft
2 main spans
Daily traffic
164
2023 count
Owner
County
County Highway Agency

About this bridge

Arlene RD over Clark Fork 105 is a prestressed concrete tee beam carrying Arlene RD over Clark Fork 105 in Missoula 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 164 vehicles a day, roughly 3% of them trucks, projected to reach 175 by 2043. The structure is 134 ft (40.8 m) long and 12 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesArlene RD
CrossesClark Fork 105
Location24M SE Missoula
RouteCounty Highway 32218
CountyMissoula County
StateMontana
Coordinates46.71764, -113.58911
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 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 geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating42.5 US tons
Inventory rating25.7 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans2 (+1 approach)
Design loadH 20
Structure length134 ft (40.8 m)
Longest span60 ft (18.3 m)
Deck width12 ft (3.7 m)
Roadway width12 ft (3.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic164 (2023)
Projected traffic175 by 2043
Trucks3%
Lanes on structure1
Traffic directionOne-lane bridge for two-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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$143,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Arlene RD over Clark Fork 105 built?

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

What condition is Arlene RD over Clark Fork 105 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 November 2023.

How much traffic does Arlene RD over Clark Fork 105 carry?

About 164 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Arlene RD over Clark Fork 105?

The structure is 134 ft (40.8 m) long with a longest span of 60 ft (18.3 m) and a deck 12 ft wide.

Who owns Arlene RD over Clark Fork 105?

It is owned by the County Highway Agency.