US Bridges

Six Mile Creek RD over Six Mile Creek 055

Fair

Park County, Montana · 6M S Emigrant · Structure no. L34209003+01001

Built
1974
51 years old, rebuilt 2008
Condition
Fair
inspected May 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
31 ft
1 main span
Daily traffic
100
2025 count
Owner
County
County Highway Agency

About this bridge

Six Mile Creek RD over Six Mile Creek 055 is a wood or timber stringer/multi-beam or girder carrying Six Mile Creek RD over Six Mile Creek 055 in Park County, Montana. It was built in 1974 and reconstructed in 2008, so it is 51 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 100 vehicles a day, roughly 3% of them trucks, projected to reach 100 by 2040. The structure is 31 ft (9.4 m) long and 16 ft wide. If it were closed, the detour would be 14.9 mi (24 km).

CarriesSix Mile Creek RD
CrossesSix Mile Creek 055
Location6M S Emigrant
RouteCounty Highway 34209
StateMontana
Coordinates45.287, -110.76695
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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 inspectionMay 2024
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 geometry7: Better than present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating60 US tons
Inventory rating42 US tons

Structure

MaterialWood or Timber
DeckSteel plate
Main spans1
Design loadUnknown
Structure length31 ft (9.4 m)
Longest span25 ft (7.5 m)
Deck width16 ft (5 m)
Roadway width15 ft (4.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic100 (2025)
Projected traffic100 by 2040
Trucks3%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed14.9 mi (24 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Six Mile Creek RD over Six Mile Creek 055 built?

It was built in 1974, making it 51 years old in 2025. It was reconstructed in 2008.

What condition is Six Mile Creek RD over Six Mile Creek 055 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 May 2024.

How much traffic does Six Mile Creek RD over Six Mile Creek 055 carry?

About 100 vehicles per day (2025 count), of which roughly 3% are trucks.

How long is Six Mile Creek RD over Six Mile Creek 055?

The structure is 31 ft (9.4 m) long with a longest span of 25 ft (7.5 m) and a deck 16 ft wide.

Who owns Six Mile Creek RD over Six Mile Creek 055?

It is owned by the County Highway Agency.