Structure 202002429 · Carter County, MT

Larson Loop RD over Box Elder Creek

Carries Larson Loop RD over Box Elder Creek, 30 M S Ekalaka.

Overall conditionGood

Set by its lowest-rated component: Deck and Superstructure and Substructure at 8 of 9.

How ratings work
Decksets the rating8/9 · Very Good
Superstructuresets the rating8/9 · Very Good
Substructuresets the rating8/9 · Very Good
Channelnot part of overall6/9 · Satisfactory
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT151 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 8/9Superstructure 8/9Substructure 8/9

151 ft end to end, longest span 74 ft: about 2 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.

Built20197 years old
Length151.2 ft46.1 m
Daily traffic100counted 2025
Last inspectedOctober 2024every 24 months

Location

StateMontana
CountyCarter
Location30 M S Ekalaka
CarriesLarson Loop RD
CrossesBox Elder Creek
Coordinates45.54559, -104.42475

Physical Characteristics

MaterialSteel
DesignStringer/Multi-beam
Total Length151.2 ft (46.1 m)
Max Span73.8 ft (22.5 m)
Deck Width24.9 ft (7.6 m)
Deck Area350.4 sq m
Main Spans2
Year Built2019

Traffic

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

Inspection & Ownership

Last InspectionOctober 2024
Inspection FrequencyEvery 24 months
OwnerCounty Highway Agency
Historical SignificanceHistorical significance is not determined
Scour Critical3 — Scour critical
Structure Number000000202002429

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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