US Bridges

East Side Road over Rock Creek

Good

Carbon County, Montana · 4M S Red Lodge · Structure no. 000000202302372

Built
2023
2 years old
Condition
Good
inspected November 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
78 ft
1 main span
Daily traffic
100
2025 count
Owner
County
County Highway Agency

About this bridge

East Side Road over Rock Creek is a steel stringer/multi-beam or girder carrying East Side Road over Rock Creek in Carbon County, Montana. It was built in 2023, so it is 2 years old, younger than the Montana average of 47 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 100 vehicles a day, roughly 3% of them trucks, projected to reach 100 by 2040. The structure is 78 ft (23.8 m) long and 30 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesEast Side Road
CrossesRock Creek
Location4M S Red Lodge
RouteCounty Highway 110
CountyCarbon County
StateMontana
Coordinates45.12067, -109.29664
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation8: Equal to present desirable criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating53.6 US tons
Inventory rating41.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckCorrugated steel
Main spans1
Design loadHL 93
Structure length78 ft (23.8 m)
Longest span76 ft (23.2 m)
Deck width30 ft (9.1 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic100 (2025)
Projected traffic100 by 2040
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was East Side Road over Rock Creek built?

It was built in 2023, making it 2 years old in 2025.

What condition is East Side Road over Rock Creek in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in November 2023.

How much traffic does East Side Road over Rock Creek carry?

About 100 vehicles per day (2025 count), of which roughly 3% are trucks.

How long is East Side Road over Rock Creek?

The structure is 78 ft (23.8 m) long with a longest span of 76 ft (23.2 m) and a deck 30 ft wide.

Who owns East Side Road over Rock Creek?

It is owned by the County Highway Agency.