Structure 11004000000091 · Flathead County, MT

Forest Road over Lower Twin Creek

Carries Forest Road over Lower Twin Creek, Cable Car Slide Area.

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 overall6/9 · Satisfactory
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
CAR · 15 FT110 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9Superstructure 7/9Substructure 7/9

110 ft end to end, longest span 68 ft. 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.

Built196561 years old
Length109.9 ft33.5 m
Daily traffic120counted 1990
Last inspectedAugust 2021every 48 months

Location

StateMontana
CountyFlathead
LocationCable Car Slide Area
CarriesForest Road
CrossesLower Twin Creek
Coordinates47.99719, -113.56533

Physical Characteristics

MaterialSteel
DesignStringer/Multi-beam
Total Length109.9 ft (33.5 m)
Max Span67.9 ft (20.7 m)
Deck Width29.9 ft (9.1 m)
Deck Area304.9 sq m
Main Spans3
Year Built1965

Traffic

Avg Daily Traffic120 (1990)
Truck Traffic4%
Lanes On Bridge2

Inspection & Ownership

Last InspectionAugust 2021
Inspection FrequencyEvery 48 months
OwnerU.S. Forest Service
Historical SignificanceHistorical significance is not determined
Scour Critical7 — Countermeasures installed
Structure Number011004000000091

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