US Bridges

Murphys LN over Yellowstone River 004

Fair

Park County, Montana · E Emigrant · Structure no. L34206000+04001

Built
1949
76 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
303 ft
4 main spans
Daily traffic
1,471
2023 count
Owner
State
State Highway Agency

About this bridge

Murphys LN over Yellowstone River 004 is a steel continuous stringer/multi-beam or girder carrying Murphys LN over Yellowstone River 004 in Park County, Montana. It was built in 1949, so it is 76 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 1,471 vehicles a day, roughly 1% of them trucks, projected to reach 1,545 by 2043. The structure is 303 ft (92.5 m) long and 25 ft wide. If it were closed, the detour would be 18 mi (29 km).

Location

Open in Google Maps
CarriesMurphys LN
CrossesYellowstone River 004
LocationE Emigrant
RouteState Highway 571
CountyPark County
StateMontana
Coordinates45.36774, -110.72697
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
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 inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating32 US tons
Inventory rating24 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadH 15
Structure length303 ft (92.5 m)
Longest span83 ft (25.3 m)
Deck width25 ft (7.5 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,471 (2023)
Projected traffic1,545 by 2043
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed18 mi (29 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 Murphys LN over Yellowstone River 004 built?

It was built in 1949, making it 76 years old in 2025.

What condition is Murphys LN over Yellowstone River 004 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 August 2024.

How much traffic does Murphys LN over Yellowstone River 004 carry?

About 1,471 vehicles per day (2023 count), of which roughly 1% are trucks.

How long is Murphys LN over Yellowstone River 004?

The structure is 303 ft (92.5 m) long with a longest span of 83 ft (25.3 m) and a deck 25 ft wide.

Who owns Murphys LN over Yellowstone River 004?

It is owned by the State Highway Agency.