Structure L47193000+04001 · Silver Bow County, MT

Palmer ST over Int Ramsey I 90 013

Carries Palmer ST over Int Ramsey I 90 013, 3m W Rocker.

Overall conditionFair

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

How ratings work
Decksets the rating6/9 · Satisfactory
Superstructure7/9 · Good
Substructure7/9 · Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT264 FT OVERALL50 FT0ELEVATION · LENGTHS TO SCALE
Deck 6/9 · sets the ratingSuperstructure 7/9Substructure 7/9

264 ft end to end, longest span 76 ft: about 4 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.

Built196759 years old
Length264.4 ft80.6 m
Daily traffic100counted 2025
Last inspectedMay 2023every 24 months

Location

StateMontana
CountySilver Bow
Location3m W Rocker
CarriesPalmer ST
CrossesInt Ramsey I 90 013
Coordinates46.00987, -112.68394

Physical Characteristics

MaterialPrestressed Concrete
DesignStringer/Multi-beam
Total Length264.4 ft (80.6 m)
Max Span75.8 ft (23.1 m)
Deck Width33.8 ft (10.3 m)
Deck Area830.2 sq m
Main Spans4
Year Built1967

Traffic

Avg Daily Traffic100 (2025)
Truck Traffic3%
Lanes On Bridge2
Lanes Under Bridge4

Inspection & Ownership

Last InspectionMay 2023
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour CriticalNot applicable
Structure NumberL47193000+04001

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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