US Bridges

US 89 over Int Vaughn-I 15

Fair

Cascade County, Montana · Vaughn · Structure no. P00003000+00001

Built
1960
65 years old
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
222 ft
4 main spans
Daily traffic
5,732
2023 count
Owner
State
State Highway Agency

About this bridge

US 89 over Int Vaughn-I 15 is a steel stringer/multi-beam or girder carrying US 89 over Int Vaughn-I 15 in Cascade County, Montana. It was built in 1960, so it is 65 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.

It carries about 5,732 vehicles a day, roughly 3% of them trucks, projected to reach 6,019 by 2043. The structure is 222 ft (67.7 m) long and 32 ft wide.

Location

Open in Google Maps
CarriesUS 89
CrossesInt Vaughn-I 15
LocationVaughn
RouteU.S. Route 89
CountyCascade County
StateMontana
Coordinates47.56266, -111.53543
Functional classRural Principal Arterial - Other

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating61 US tons
Inventory rating47 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length222 ft (67.7 m)
Longest span67 ft (20.3 m)
Deck width32 ft (9.8 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,732 (2023)
Projected traffic6,019 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed—
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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$627,000
NavigationNot applicable (no waterway)

Frequently asked questions

When was US 89 over Int Vaughn-I 15 built?

It was built in 1960, making it 65 years old in 2025.

What condition is US 89 over Int Vaughn-I 15 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 2024.

How much traffic does US 89 over Int Vaughn-I 15 carry?

About 5,732 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is US 89 over Int Vaughn-I 15?

The structure is 222 ft (67.7 m) long with a longest span of 67 ft (20.3 m) and a deck 32 ft wide.

Who owns US 89 over Int Vaughn-I 15?

It is owned by the State Highway Agency.