US Bridges

SH 81 over Marsh Creek

Fair

Cassia County, Idaho · In Declo Ecl · Structure no. 000000000016616

Built
2013
12 years old
Condition
Fair
inspected March 2021
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
47 ft
1 main span
Daily traffic
2,600
2023 count
Owner
State
State Highway Agency

About this bridge

SH 81 over Marsh Creek is a prestressed concrete box beam or girders - multiple carrying SH 81 over Marsh Creek in Cassia County, Idaho. It was built in 2013, so it is 12 years old, younger than the Idaho average of 45.3 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 2,600 vehicles a day, roughly 4% of them trucks, projected to reach 3,900 by 2042. The structure is 47 ft (14.3 m) long and 40 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesSH 81
CrossesMarsh Creek
LocationIn Declo Ecl
RouteState Highway 81
CountyCassia County
StateIdaho
Coordinates42.52042, -113.625
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionMarch 2021
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
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 rating67.5 US tons
Inventory rating52.1 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHL 93
Structure length47 ft (14.3 m)
Longest span44 ft (13.4 m)
Deck width40 ft (12.2 m)
Roadway width37 ft (11.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,600 (2023)
Projected traffic3,900 by 2042
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was SH 81 over Marsh Creek built?

It was built in 2013, making it 12 years old in 2025.

What condition is SH 81 over Marsh Creek 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 March 2021.

How much traffic does SH 81 over Marsh Creek carry?

About 2,600 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is SH 81 over Marsh Creek?

The structure is 47 ft (14.3 m) long with a longest span of 44 ft (13.4 m) and a deck 40 ft wide.

Who owns SH 81 over Marsh Creek?

It is owned by the State Highway Agency.