US Bridges

Southside Crossing over Clark Fork 015

Fair

Mineral County, Montana · N Dry Creek Int · Structure no. L31169000+01001

Built
1982
43 years old
Condition
Fair
inspected July 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
429 ft
3 main spans
Daily traffic
299
2023 count
Owner
State
State Highway Agency

About this bridge

Southside Crossing over Clark Fork 015 is a steel continuous stringer/multi-beam or girder carrying Southside Crossing over Clark Fork 015 in Mineral County, Montana. It was built in 1982, so it is 43 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 299 vehicles a day, roughly 3% of them trucks, projected to reach 320 by 2043. The structure is 429 ft (130.9 m) long and 34 ft wide. If it were closed, the detour would be 14.9 mi (24 km).

Location

Open in Google Maps
CarriesSouthside Crossing
CrossesClark Fork 015
LocationN Dry Creek Int
RouteState Highway 31169
CountyMineral County
StateMontana
Coordinates47.22876, -114.96593
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating26 US tons
Inventory rating20 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length429 ft (130.9 m)
Longest span163 ft (49.7 m)
Deck width34 ft (10.5 m)
Roadway width31 ft (9.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic299 (2023)
Projected traffic320 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed14.9 mi (24 km)
TollOn a free road
National Highway SystemNo

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 Southside Crossing over Clark Fork 015 built?

It was built in 1982, making it 43 years old in 2025.

What condition is Southside Crossing over Clark Fork 015 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 2023.

How much traffic does Southside Crossing over Clark Fork 015 carry?

About 299 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Southside Crossing over Clark Fork 015?

The structure is 429 ft (130.9 m) long with a longest span of 163 ft (49.7 m) and a deck 34 ft wide.

Who owns Southside Crossing over Clark Fork 015?

It is owned by the State Highway Agency.