US Bridges

Old HWY 10 E over O`fallon Creek 043

Fair

Prairie County, Montana · 1M W Fallon · Structure no. L40004021+03001

Built
1948
77 years old
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
224 ft
2 main spans
Daily traffic
507
2023 count
Owner
State
State Highway Agency

About this bridge

Old HWY 10 E over O`fallon Creek 043 is a steel continuous stringer/multi-beam or girder carrying Old HWY 10 E over O`fallon Creek 043 in Prairie County, Montana. It was built in 1948, so it is 77 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 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 507 vehicles a day, roughly 3% of them trucks, projected to reach 540 by 2043. The structure is 224 ft (68.3 m) long and 32 ft wide. If it were closed, the detour would be 16.2 mi (26 km).

Location

Open in Google Maps
CarriesOld HWY 10 E
CrossesO`fallon Creek 043
Location1M W Fallon
RouteState Highway 81020
CountyPrairie County
StateMontana
Coordinates46.82978, -105.14453
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating23 US tons
Inventory rating18 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 15
Structure length224 ft (68.3 m)
Longest span110 ft (33.5 m)
Deck width32 ft (9.7 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic507 (2023)
Projected traffic540 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed16.2 mi (26 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 Old HWY 10 E over O`fallon Creek 043 built?

It was built in 1948, making it 77 years old in 2025.

What condition is Old HWY 10 E over O`fallon Creek 043 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 Old HWY 10 E over O`fallon Creek 043 carry?

About 507 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Old HWY 10 E over O`fallon Creek 043?

The structure is 224 ft (68.3 m) long with a longest span of 110 ft (33.5 m) and a deck 32 ft wide.

Who owns Old HWY 10 E over O`fallon Creek 043?

It is owned by the State Highway Agency.