US Bridges

Miller Road over Fort Belknap Canal 057

FairPosted for load

Blaine County, Montana · 7M NW Harlem · Structure no. L03156000+07001

Built
1923
102 years old
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
52 ft
1 main span
Daily traffic
100
2025 count
Owner
County
County Highway Agency

About this bridge

Miller Road over Fort Belknap Canal 057 is a steel stringer/multi-beam or girder carrying Miller Road over Fort Belknap Canal 057 in Blaine County, Montana. It was built in 1923, so it is 102 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 6 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 52 ft (15.8 m) long and 16 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

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CarriesMiller Road
CrossesFort Belknap Canal 057
Location7M NW Harlem
RouteCounty Highway 3031
CountyBlaine County
StateMontana
Coordinates48.5755, -108.91452
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2023
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 geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating5 US tons
Inventory rating5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckWood or timber
Main spans1
Design loadUnknown
Structure length52 ft (15.8 m)
Longest span52 ft (15.8 m)
Deck width16 ft (4.9 m)
Roadway width16 ft (4.9 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 closed123.7 mi (199 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$141,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Miller Road over Fort Belknap Canal 057 built?

It was built in 1923, making it 102 years old in 2025.

What condition is Miller Road over Fort Belknap Canal 057 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 April 2023.

How much traffic does Miller Road over Fort Belknap Canal 057 carry?

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

How long is Miller Road over Fort Belknap Canal 057?

The structure is 52 ft (15.8 m) long with a longest span of 52 ft (15.8 m) and a deck 16 ft wide.

Who owns Miller Road over Fort Belknap Canal 057?

It is owned by the County Highway Agency.