US Bridges

S 471 FH 7 over Prospect Creek

Fair

Sanders County, Montana · 14M W Thompson Falls · Structure no. S00471011+02691

Built
1979
46 years old
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
95 ft
1 main span
Daily traffic
138
2023 count
Owner
State
State Highway Agency

About this bridge

S 471 FH 7 over Prospect Creek is a prestressed concrete stringer/multi-beam or girder carrying S 471 FH 7 over Prospect Creek in Sanders County, Montana. It was built in 1979, so it is 46 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 138 vehicles a day, roughly 5% of them trucks, projected to reach 145 by 2043. The structure is 95 ft (29 m) long and 35 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesS 471 FH 7
CrossesProspect Creek
Location14M W Thompson Falls
RouteState Highway 471
CountySanders County
StateMontana
Coordinates47.53874, -115.54569
Functional classRural Major 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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating76.9 US tons
Inventory rating36 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length95 ft (29 m)
Longest span95 ft (29 m)
Deck width35 ft (10.7 m)
Roadway width31 ft (9.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic138 (2023)
Projected traffic145 by 2043
Trucks5%
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

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 S 471 FH 7 over Prospect Creek built?

It was built in 1979, making it 46 years old in 2025.

What condition is S 471 FH 7 over Prospect Creek 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 S 471 FH 7 over Prospect Creek carry?

About 138 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is S 471 FH 7 over Prospect Creek?

The structure is 95 ft (29 m) long with a longest span of 95 ft (29 m) and a deck 35 ft wide.

Who owns S 471 FH 7 over Prospect Creek?

It is owned by the State Highway Agency.