US Bridges

Melrose RD over Big Hole River 036

Fair

Madison County, Montana · 2M W Twin Bridges · Structure no. L29281018+07001

Built
1978
47 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
242 ft
2 main spans
Daily traffic
157
2023 count
Owner
County
County Highway Agency

About this bridge

Melrose RD over Big Hole River 036 is a prestressed concrete stringer/multi-beam or girder carrying Melrose RD over Big Hole River 036 in Madison County, Montana. It was built in 1978, so it is 47 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 157 vehicles a day, roughly 3% of them trucks, projected to reach 168 by 2043. The structure is 242 ft (73.8 m) long and 34 ft wide. If it were closed, the detour would be 44.7 mi (72 km).

Location

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CarriesMelrose RD
CrossesBig Hole River 036
Location2M W Twin Bridges
RouteCounty Highway 29101
CountyMadison County
StateMontana
Coordinates45.54826, -112.36483
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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
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 rating61.9 US tons
Inventory rating28 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length242 ft (73.8 m)
Longest span120 ft (36.6 m)
Deck width34 ft (10.5 m)
Roadway width31 ft (9.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic157 (2023)
Projected traffic168 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed44.7 mi (72 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 Melrose RD over Big Hole River 036 built?

It was built in 1978, making it 47 years old in 2025.

What condition is Melrose RD over Big Hole River 036 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 Melrose RD over Big Hole River 036 carry?

About 157 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Melrose RD over Big Hole River 036?

The structure is 242 ft (73.8 m) long with a longest span of 120 ft (36.6 m) and a deck 34 ft wide.

Who owns Melrose RD over Big Hole River 036?

It is owned by the County Highway Agency.