US Bridges

Horse Ranch Road over Armells Creek

Good

Cascade County, Montana · 3.9 Miles North of Irish · Structure no. AFMTNZBX85161

Built
2017
8 years old
Condition
Good
inspected September 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
78 ft
1 main span
Daily traffic
20
2017 count
Owner
Federal
Air Force

About this bridge

Horse Ranch Road over Armells Creek is a prestressed concrete stringer/multi-beam or girder carrying Horse Ranch Road over Armells Creek in Cascade County, Montana. It was built in 2017, so it is 8 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 20 vehicles a day, projected to reach 24 by 2037. The structure is 78 ft (23.8 m) long and 28 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

CarriesHorse Ranch Road
CrossesArmells Creek
Location3.9 Miles North of Irish
StateMontana
Coordinates47.39637, -109.13187
Functional classRural Local

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than 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 rating80 US tons
Inventory rating48 US tons

Structure

MaterialPrestressed Concrete
DeckOther
Main spans1
Design loadHL 93
Structure length78 ft (23.8 m)
Longest span75 ft (22.9 m)
Deck width28 ft (8.5 m)
Roadway width25 ft (7.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic20 (2017)
Projected traffic24 by 2037
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerAir Force
Maintained byAir Force
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 Horse Ranch Road over Armells Creek built?

It was built in 2017, making it 8 years old in 2025.

What condition is Horse Ranch Road over Armells 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 September 2024.

How much traffic does Horse Ranch Road over Armells Creek carry?

About 20 vehicles per day (2017 count).

How long is Horse Ranch Road over Armells Creek?

The structure is 78 ft (23.8 m) long with a longest span of 75 ft (22.9 m) and a deck 28 ft wide.

Who owns Horse Ranch Road over Armells Creek?

It is owned by the Air Force.