US Bridges

Flat Creek Road over Sutton Creek

Fair

Lincoln County, Montana · Sutton Creek · Structure no. 011401000000075

Built
1980
45 years old
Condition
Fair
inspected September 2021
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
32 ft
1 main span
Daily traffic
40
Owner
Federal
U.S. Forest Service

About this bridge

Flat Creek Road over Sutton Creek is a prestressed concrete stringer/multi-beam or girder carrying Flat Creek Road over Sutton Creek in Lincoln County, Montana. It was built in 1980, so it is 45 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 40 vehicles a day, projected to reach 60 by 2045. The structure is 32 ft (9.8 m) long and 20 ft wide. If it were closed, the detour would be 39.8 mi (64 km).

Location

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CarriesFlat Creek Road
CrossesSutton Creek
LocationSutton Creek
RouteFederal Lands Road 7993
CountyLincoln County
StateMontana
Coordinates48.76035, -115.24787
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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2021
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating51 US tons
Inventory rating39.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckOther
Main spans1
Design loadHS 20
Structure length32 ft (9.8 m)
Longest span31 ft (9.4 m)
Deck width20 ft (6.1 m)
Roadway width19 ft (5.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic40 (—)
Projected traffic60 by 2045
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed39.8 mi (64 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerU.S. Forest Service
Maintained byU.S. Forest Service
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Flat Creek Road over Sutton Creek built?

It was built in 1980, making it 45 years old in 2025.

What condition is Flat Creek Road over Sutton 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 September 2021.

How much traffic does Flat Creek Road over Sutton Creek carry?

About 40 vehicles per day (latest count).

How long is Flat Creek Road over Sutton Creek?

The structure is 32 ft (9.8 m) long with a longest span of 31 ft (9.4 m) and a deck 20 ft wide.

Who owns Flat Creek Road over Sutton Creek?

It is owned by the U.S. Forest Service.