US Bridges

0427: Mcnamara Roa over Belmont Creek

Good

Missoula County, Montana · 8 MI NE of Johnsrud RD / · Structure no. 0000000L2126964

Built
2020
5 years old
Condition
Good
inspected August 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
36 ft
1 main span
Daily traffic
25
2022 count
Owner
Federal
Bureau of Land Management

About this bridge

0427: Mcnamara Roa over Belmont Creek is a steel stringer/multi-beam or girder carrying 0427: Mcnamara Roa over Belmont Creek in Missoula County, Montana. It was built in 2020, so it is 5 years old, younger than the Montana average of 47 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 25 vehicles a day, projected to reach 30 by 2040. The structure is 36 ft (11.1 m) long and 17 ft wide. If it were closed, the detour would be 14.9 mi (24 km).

Location

Open in Google Maps
Carries0427: Mcnamara Roa
CrossesBelmont Creek
Location8 MI NE of Johnsrud RD /
RouteFederal Lands Road 0
CountyMissoula County
StateMontana
Coordinates46.96285, -113.57419
Functional classRural Minor Collector

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation8: Equal to present desirable criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating53.6 US tons
Inventory rating41.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckCorrugated steel
Main spans1
Design loadHL 93
Structure length36 ft (11.1 m)
Longest span35 ft (10.7 m)
Deck width17 ft (5.2 m)
Roadway width16 ft (4.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic25 (2022)
Projected traffic30 by 2040
Trucks—
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

OwnerBureau of Land Management
Maintained byBureau of Land Management
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was 0427: Mcnamara Roa over Belmont Creek built?

It was built in 2020, making it 5 years old in 2025.

What condition is 0427: Mcnamara Roa over Belmont Creek in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in August 2024.

How much traffic does 0427: Mcnamara Roa over Belmont Creek carry?

About 25 vehicles per day (2022 count).

How long is 0427: Mcnamara Roa over Belmont Creek?

The structure is 36 ft (11.1 m) long with a longest span of 35 ft (10.7 m) and a deck 17 ft wide.

Who owns 0427: Mcnamara Roa over Belmont Creek?

It is owned by the Bureau of Land Management.