Structure I00015045+09002 · Beaverhead County, MT

I 15 over Beaverhd R-high Brdg RD

Carries I 15 over Beaverhd R-high Brdg RD, 1.2m N Clark Canyon Dam.

Overall conditionFair

Set by its lowest-rated component: Deck and Superstructure and Substructure at 6 of 9.

How ratings work
Decksets the rating6/9 · Satisfactory
Superstructuresets the rating6/9 · Satisfactory
Substructuresets the rating6/9 · Satisfactory
Channelnot part of overall7/9 · Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT448 FT OVERALL50 FT0ELEVATION · LENGTHS TO SCALE
Deck 6/9Superstructure 6/9Substructure 6/9

448 ft end to end, longest span 100 ft: about 6 semi-trucks nose to tail. Lengths and the semi-truck on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a multi-beam bridge.

Built198145 years old
Length448.2 ft136.6 m
Daily traffic2,185counted 2023
Last inspectedJune 2023every 24 months

Location

StateMontana
CountyBeaverhead
Location1.2m N Clark Canyon Dam
CarriesI 15
CrossesBeaverhd R-high Brdg RD
Coordinates45.01809, -112.83922

Physical Characteristics

MaterialPrestressed Concrete
DesignStringer/Multi-beam
Total Length448.2 ft (136.6 m)
Max Span100.1 ft (30.5 m)
Deck Width44.9 ft (13.7 m)
Deck Area1871.4 sq m
Main Spans5
Year Built1981

Traffic

Avg Daily Traffic2,185 (2023)
Truck Traffic25%
Lanes On Bridge2
Lanes Under Bridge2

Inspection & Ownership

Last InspectionJune 2023
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical5 — Stable for scour
Structure NumberI00015045+09002

How Bridge Ratings Work

Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."

0Failed
1Imminent failure
2Critical
3Serious
4Poor
5Fair
6Satisfactory
7Good
8Very good
9Excellent
Good · lowest component 7–9
Fair · lowest component 5–6
Poor · lowest component 0–4

A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.

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