US Bridges

Boulder RD over Speculator Creek 011

Fair

Sweet Grass County, Montana · 20M S Mcleod · Structure no. L49102008+05001

Built
1965
60 years old, rebuilt 1970
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
27 ft
1 main span
Daily traffic
157
2023 count
Owner
County
County Highway Agency

About this bridge

Boulder RD over Speculator Creek 011 is a wood or timber stringer/multi-beam or girder carrying Boulder RD over Speculator Creek 011 in Sweet Grass County, Montana. It was built in 1965 and reconstructed in 1970, so it is 60 years old, older than the Montana average of 47 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 157 vehicles a day, roughly 17% of them trucks, projected to reach 165 by 2043. The structure is 27 ft (8.2 m) long and 15 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesBoulder RD
CrossesSpeculator Creek 011
Location20M S Mcleod
RouteCounty Highway 49102
CountySweet Grass County
StateMontana
Coordinates45.38849, -110.20184
Functional classRural Major Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating44.6 US tons
Inventory rating32.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadHS 20
Structure length27 ft (8.2 m)
Longest span24 ft (7.3 m)
Deck width15 ft (4.6 m)
Roadway width14 ft (4.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic157 (2023)
Projected traffic165 by 2043
Trucks17%
Lanes on structure1
Traffic directionOne-lane bridge for two-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 Boulder RD over Speculator Creek 011 built?

It was built in 1965, making it 60 years old in 2025. It was reconstructed in 1970.

What condition is Boulder RD over Speculator Creek 011 in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in July 2024.

How much traffic does Boulder RD over Speculator Creek 011 carry?

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

How long is Boulder RD over Speculator Creek 011?

The structure is 27 ft (8.2 m) long with a longest span of 24 ft (7.3 m) and a deck 15 ft wide.

Who owns Boulder RD over Speculator Creek 011?

It is owned by the County Highway Agency.