US Bridges

US 87 over Ross Fork Creek

Good

Judith Basin County, Montana · 3M E Hobson · Structure no. P00057062+05331

Built
1971
54 years old
Condition
Good
inspected March 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
179 ft
3 main spans
Daily traffic
3,335
2023 count
Owner
State
State Highway Agency

About this bridge

US 87 over Ross Fork Creek is a prestressed concrete stringer/multi-beam or girder carrying US 87 over Ross Fork Creek in Judith Basin County, Montana. It was built in 1971, so it is 54 years old, older than the Montana average of 47 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 3,335 vehicles a day, roughly 14% of them trucks, projected to reach 3,502 by 2043. The structure is 179 ft (54.6 m) long and 46 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesUS 87
CrossesRoss Fork Creek
Location3M E Hobson
RouteU.S. Route 87
CountyJudith Basin County
StateMontana
Coordinates46.99544, -109.79259
Functional classRural Principal Arterial - Other

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 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 geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating35.1 US tons
Inventory rating24 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length179 ft (54.6 m)
Longest span67 ft (20.4 m)
Deck width46 ft (14 m)
Roadway width44 ft (13.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,335 (2023)
Projected traffic3,502 by 2043
Trucks14%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkNon-Interstate STRAHNET route

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 US 87 over Ross Fork Creek built?

It was built in 1971, making it 54 years old in 2025.

What condition is US 87 over Ross Fork Creek in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in March 2023.

How much traffic does US 87 over Ross Fork Creek carry?

About 3,335 vehicles per day (2023 count), of which roughly 14% are trucks.

How long is US 87 over Ross Fork Creek?

The structure is 179 ft (54.6 m) long with a longest span of 67 ft (20.4 m) and a deck 46 ft wide.

Who owns US 87 over Ross Fork Creek?

It is owned by the State Highway Agency.