US Bridges

S 297 over Deadman`s Basin Canal

Fair

Wheatland County, Montana · 1M N Shawmut · Structure no. S00297000+09001

Built
1959
66 years old
Condition
Fair
inspected October 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
58 ft
3 main spans
Daily traffic
79
2023 count
Owner
State
State Highway Agency

About this bridge

S 297 over Deadman`s Basin Canal is a wood or timber stringer/multi-beam or girder carrying S 297 over Deadman`s Basin Canal in Wheatland County, Montana. It was built in 1959, so it is 66 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 79 vehicles a day, roughly 1% of them trucks, projected to reach 83 by 2043. The structure is 58 ft (17.7 m) long and 26 ft wide. If it were closed, the detour would be 29.8 mi (48 km).

Location

Open in Google Maps
CarriesS 297
CrossesDeadman`s Basin Canal
Location1M N Shawmut
RouteState Highway 297
CountyWheatland County
StateMontana
Coordinates46.3584, -109.52812
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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionOctober 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 geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating42 US tons
Inventory rating30 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans3
Design loadHS 15
Structure length58 ft (17.7 m)
Longest span19 ft (5.8 m)
Deck width26 ft (7.9 m)
Roadway width24 ft (7.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic79 (2023)
Projected traffic83 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 297 over Deadman`s Basin Canal built?

It was built in 1959, making it 66 years old in 2025.

What condition is S 297 over Deadman`s Basin Canal 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 October 2024.

How much traffic does S 297 over Deadman`s Basin Canal carry?

About 79 vehicles per day (2023 count), of which roughly 1% are trucks.

How long is S 297 over Deadman`s Basin Canal?

The structure is 58 ft (17.7 m) long with a longest span of 19 ft (5.8 m) and a deck 26 ft wide.

Who owns S 297 over Deadman`s Basin Canal?

It is owned by the State Highway Agency.