US Bridges

S 1 over Boulder Creek

Fair

Granite County, Montana · Maxville · Structure no. P00019049+00211

Built
1986
39 years old
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
84 ft
1 main span
Daily traffic
1,144
2023 count
Owner
State
State Highway Agency

About this bridge

S 1 over Boulder Creek is a prestressed concrete stringer/multi-beam or girder carrying S 1 over Boulder Creek in Granite County, Montana. It was built in 1986, so it is 39 years old, younger 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 6 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 1,144 vehicles a day, roughly 1% of them trucks, projected to reach 1,304 by 2043. The structure is 84 ft (25.6 m) long and 36 ft wide. If it were closed, the detour would be 29.8 mi (48 km).

Location

Open in Google Maps
CarriesS 1
CrossesBoulder Creek
LocationMaxville
RouteState Highway 1
CountyGranite County
StateMontana
Coordinates46.47019, -113.23467
Functional classRural Minor Arterial

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating47 US tons
Inventory rating28 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length84 ft (25.6 m)
Longest span78 ft (23.8 m)
Deck width36 ft (11.1 m)
Roadway width33 ft (10.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,144 (2023)
Projected traffic1,304 by 2043
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed29.8 mi (48 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 S 1 over Boulder Creek built?

It was built in 1986, making it 39 years old in 2025.

What condition is S 1 over Boulder Creek 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 S 1 over Boulder Creek carry?

About 1,144 vehicles per day (2023 count), of which roughly 1% are trucks.

How long is S 1 over Boulder Creek?

The structure is 84 ft (25.6 m) long with a longest span of 78 ft (23.8 m) and a deck 36 ft wide.

Who owns S 1 over Boulder Creek?

It is owned by the State Highway Agency.