US Bridges

Marias Valley RD over Marias River 001

Fair

Toole County, Montana · 5M S Shelby · Structure no. L51306003+02001

Built
1936
89 years old
Condition
Fair
inspected October 2023
Type
Girder and Floorbeam System
Steel Continuous
Length
545 ft
2 main spans
Daily traffic
511
2023 count
Owner
State
State Highway Agency

About this bridge

Marias Valley RD over Marias River 001 is a steel continuous girder and floorbeam system carrying Marias Valley RD over Marias River 001 in Toole County, Montana. It was built in 1936, so it is 89 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 511 vehicles a day, roughly 3% of them trucks, projected to reach 539 by 2043. The structure is 545 ft (166.1 m) long and 27 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

Open in Google Maps
CarriesMarias Valley RD
CrossesMarias River 001
Location5M S Shelby
RouteState Highway 81007
CountyToole County
StateMontana
Coordinates48.42701, -111.89101
Functional classRural Local

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no 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 geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating48 US tons
Inventory rating29 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2 (+4 approach)
Design loadH 15
Structure length545 ft (166.1 m)
Longest span120 ft (36.7 m)
Deck width27 ft (8.3 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic511 (2023)
Projected traffic539 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed9.9 mi (16 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 Marias Valley RD over Marias River 001 built?

It was built in 1936, making it 89 years old in 2025.

What condition is Marias Valley RD over Marias River 001 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 2023.

How much traffic does Marias Valley RD over Marias River 001 carry?

About 511 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Marias Valley RD over Marias River 001?

The structure is 545 ft (166.1 m) long with a longest span of 120 ft (36.7 m) and a deck 27 ft wide.

Who owns Marias Valley RD over Marias River 001?

It is owned by the State Highway Agency.