US Bridges

I 15 over Beaverhd R-High Brdg RD

Fair

Beaverhead County, Montana · 1.2M N Clark Canyon Dam · Structure no. I00015045+09001

Built
1964
61 years old
Condition
Fair
inspected June 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
402 ft
5 main spans
Daily traffic
2,185
2023 count
Owner
State
State Highway Agency

About this bridge

I 15 over Beaverhd R-High Brdg RD is a steel stringer/multi-beam or girder carrying I 15 over Beaverhd R-High Brdg RD in Beaverhead County, Montana. It was built in 1964, so it is 61 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 5 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 2,185 vehicles a day, roughly 25% of them trucks, projected to reach 2,338 by 2043. The structure is 402 ft (122.5 m) long and 32 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 15
CrossesBeaverhd R-High Brdg RD
Location1.2M N Clark Canyon Dam
RouteInterstate 15
CountyBeaverhead County
StateMontana
Coordinates45.01786, -112.83909
Functional classRural Principal Arterial - Interstate

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating34 US tons
Inventory rating26 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20
Structure length402 ft (122.5 m)
Longest span100 ft (30.5 m)
Deck width32 ft (9.7 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,185 (2023)
Projected traffic2,338 by 2043
Trucks25%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway and waterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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$1.1 million
NavigationNo navigation control on waterway

Frequently asked questions

When was I 15 over Beaverhd R-High Brdg RD built?

It was built in 1964, making it 61 years old in 2025.

What condition is I 15 over Beaverhd R-High Brdg RD 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 June 2023.

How much traffic does I 15 over Beaverhd R-High Brdg RD carry?

About 2,185 vehicles per day (2023 count), of which roughly 25% are trucks.

How long is I 15 over Beaverhd R-High Brdg RD?

The structure is 402 ft (122.5 m) long with a longest span of 100 ft (30.5 m) and a deck 32 ft wide.

Who owns I 15 over Beaverhd R-High Brdg RD?

It is owned by the State Highway Agency.