US Bridges

SH 77 over Marsh Creek

Fair

Cassia County, Idaho · Near Declo Ncl · Structure no. 000000000015240

Built
1960
65 years old
Condition
Fair
inspected March 2021
Type
Frame
Concrete
Length
24 ft
1 main span
Daily traffic
4,900
2023 count
Owner
State
State Highway Agency

About this bridge

SH 77 over Marsh Creek is a concrete frame carrying SH 77 over Marsh Creek in Cassia County, Idaho. It was built in 1960, so it is 65 years old, older 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 4,900 vehicles a day, roughly 3% of them trucks, projected to reach 7,350 by 2042. The structure is 24 ft (7.3 m) long and 60 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesSH 77
CrossesMarsh Creek
LocationNear Declo Ncl
RouteState Highway 77
CountyCassia County
StateIdaho
Coordinates42.52092, -113.62814
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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
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 geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating61.9 US tons
Inventory rating37 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length24 ft (7.3 m)
Longest span24 ft (7.3 m)
Deck width60 ft (18.3 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,900 (2023)
Projected traffic7,350 by 2042
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.9 mi (3 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 77 over Marsh Creek built?

It was built in 1960, making it 65 years old in 2025.

What condition is SH 77 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 77 over Marsh Creek carry?

About 4,900 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is SH 77 over Marsh Creek?

The structure is 24 ft (7.3 m) long with a longest span of 24 ft (7.3 m) and a deck 60 ft wide.

Who owns SH 77 over Marsh Creek?

It is owned by the State Highway Agency.