US Bridges

S 80 over Butte Creek

FairPosted for load

Chouteau County, Montana · 6M SE Square Butte · Structure no. P00080041+03871

Built
1950
75 years old, rebuilt 1964
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
77 ft
3 main spans
Daily traffic
158
2023 count
Owner
State
State Highway Agency

About this bridge

S 80 over Butte Creek is a wood or timber stringer/multi-beam or girder carrying S 80 over Butte Creek in Chouteau County, Montana. It was built in 1950 and reconstructed in 1964, so it is 75 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. Its operating status is: posted for load restriction.

It carries about 158 vehicles a day, roughly 17% of them trucks, projected to reach 166 by 2043. The structure is 77 ft (23.5 m) long and 30 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

CarriesS 80
CrossesButte Creek
Location6M SE Square Butte
RouteState Highway 80
StateMontana
Coordinates47.45819, -110.10856
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
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating41 US tons
Inventory rating28 US tons

Structure

MaterialWood or Timber
DeckWood or timber
Main spans3
Design loadH 15
Structure length77 ft (23.5 m)
Longest span25 ft (7.7 m)
Deck width30 ft (9.1 m)
Roadway width29 ft (8.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic158 (2023)
Projected traffic166 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

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 80 over Butte Creek built?

It was built in 1950, making it 75 years old in 2025. It was reconstructed in 1964.

What condition is S 80 over Butte 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 September 2024.

How much traffic does S 80 over Butte Creek carry?

About 158 vehicles per day (2023 count), of which roughly 17% are trucks.

How long is S 80 over Butte Creek?

The structure is 77 ft (23.5 m) long with a longest span of 25 ft (7.7 m) and a deck 30 ft wide.

Who owns S 80 over Butte Creek?

It is owned by the State Highway Agency.