US Bridges

Bannack Bench RD over Horse Praire Creek 010

FairPosted for load

Beaverhead County, Montana · 1M N Grant · Structure no. L01008001+08001

Built
1981
44 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
40 ft
1 main span
Daily traffic
100
2025 count
Owner
County
County Highway Agency

About this bridge

Bannack Bench RD over Horse Praire Creek 010 is a steel stringer/multi-beam or girder carrying Bannack Bench RD over Horse Praire Creek 010 in Beaverhead County, Montana. It was built in 1981, so it is 44 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 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. Its operating status is: posted for load restriction.

It carries about 100 vehicles a day, roughly 3% of them trucks, projected to reach 100 by 2040. The structure is 40 ft (12.2 m) long and 20 ft wide. If it were closed, the detour would be 55.3 mi (89 km).

CarriesBannack Bench RD
CrossesHorse Praire Creek 010
Location1M N Grant
RouteCounty Highway 1008
StateMontana
Coordinates45.02517, -113.05637
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation2: Basically intolerable, requiring high priority of replacement
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating5 US tons
Inventory rating5 US tons

Structure

MaterialSteel
DeckSteel plate
Main spans1
Design loadUnknown
Structure length40 ft (12.2 m)
Longest span31 ft (9.4 m)
Deck width20 ft (6.1 m)
Roadway width19 ft (5.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic100 (2025)
Projected traffic100 by 2040
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed55.3 mi (89 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$150,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Bannack Bench RD over Horse Praire Creek 010 built?

It was built in 1981, making it 44 years old in 2025.

What condition is Bannack Bench RD over Horse Praire Creek 010 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 August 2024.

How much traffic does Bannack Bench RD over Horse Praire Creek 010 carry?

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

How long is Bannack Bench RD over Horse Praire Creek 010?

The structure is 40 ft (12.2 m) long with a longest span of 31 ft (9.4 m) and a deck 20 ft wide.

Who owns Bannack Bench RD over Horse Praire Creek 010?

It is owned by the County Highway Agency.