Structure I00090205+07152 · Deer Lodge County, MT

I 90 over Clark Fork River

Carries I 90 over Clark Fork River, 2.5m N Opportunity.

Overall conditionGood

Set by its lowest-rated component: Deck and Superstructure and Substructure at 7 of 9.

How ratings work
Decksets the rating7/9 · Good
Superstructuresets the rating7/9 · Good
Substructuresets the rating7/9 · Good
Channelnot part of overall8/9 · Very Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
CAR · 15 FT86 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9Superstructure 7/9Substructure 7/9

86 ft end to end. Lengths and the car 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.

Built197848 years old
Length86.0 ft26.2 m
Daily traffic5,209counted 2023
Last inspectedMarch 2024every 24 months

Location

StateMontana
CountyDeer Lodge
Location2.5m N Opportunity
CarriesI 90
CrossesClark Fork River
Coordinates46.12239, -112.79864

Physical Characteristics

MaterialPrestressed Concrete
DesignStringer/Multi-beam
Total Length86.0 ft (26.2 m)
Max Span85.0 ft (25.9 m)
Deck Width44.3 ft (13.5 m)
Deck Area353.7 sq m
Main Spans1
Year Built1978

Traffic

Avg Daily Traffic5,209 (2023)
Truck Traffic24%
Lanes On Bridge2

Inspection & Ownership

Last InspectionMarch 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical8 — Stable, low risk
Structure NumberI00090205+07152

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.

Nearby Bridges