US Bridges

Boulder RD over Boulder River 003

Good

Sweet Grass County, Montana · 12M S Mcleod · Structure no. 000000000004519

Built
2017
8 years old
Condition
Good
inspected June 2023
Type
Stringer/Multi-beam or Girder
Concrete Continuous
Length
126 ft
1 main span
Daily traffic
157
2023 count
Owner
County
County Highway Agency

About this bridge

Boulder RD over Boulder River 003 is a concrete continuous stringer/multi-beam or girder carrying Boulder RD over Boulder River 003 in Sweet Grass County, Montana. It was built in 2017, so it is 8 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 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 157 vehicles a day, roughly 17% of them trucks, projected to reach 165 by 2043. The structure is 126 ft (38.4 m) long and 31 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesBoulder RD
CrossesBoulder River 003
Location12M S Mcleod
RouteCounty Highway 49102
CountySweet Grass County
StateMontana
Coordinates45.48739, -110.217
Functional classRural Major Collector

Condition and inspection

Good

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating57 US tons
Inventory rating38 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length126 ft (38.4 m)
Longest span120 ft (36.5 m)
Deck width31 ft (9.3 m)
Roadway width27 ft (8.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic157 (2023)
Projected traffic165 by 2043
Trucks17%
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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$90,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Boulder RD over Boulder River 003 built?

It was built in 2017, making it 8 years old in 2025.

What condition is Boulder RD over Boulder River 003 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 June 2023.

How much traffic does Boulder RD over Boulder River 003 carry?

About 157 vehicles per day (2023 count), of which roughly 17% are trucks.

How long is Boulder RD over Boulder River 003?

The structure is 126 ft (38.4 m) long with a longest span of 120 ft (36.5 m) and a deck 31 ft wide.

Who owns Boulder RD over Boulder River 003?

It is owned by the County Highway Agency.