US Bridges

STC2818;E Fork RD over Big Wood River

Fair

Blaine County, Idaho · 6.0 N. 1.6 W. Hailey · Structure no. 000000000019570

Built
1974
51 years old
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
101 ft
1 main span
Daily traffic
2,800
2023 count
Owner
County
County Highway Agency

About this bridge

STC2818;E Fork RD over Big Wood River is a prestressed concrete stringer/multi-beam or girder carrying STC2818;E Fork RD over Big Wood River in Blaine County, Idaho. It was built in 1974, so it is 51 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 2,800 vehicles a day, roughly 4% of them trucks, projected to reach 4,200 by 2042. The structure is 101 ft (30.8 m) long and 32 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesSTC2818;E Fork RD
CrossesBig Wood River
Location6.0 N. 1.6 W. Hailey
RouteCounty Highway 2818
CountyBlaine County
StateIdaho
Coordinates43.60492, -114.34672
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.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 2024
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 geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating67 US tons
Inventory rating24 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length101 ft (30.8 m)
Longest span98 ft (29.9 m)
Deck width32 ft (9.7 m)
Roadway width29 ft (8.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,800 (2023)
Projected traffic4,200 by 2042
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$1.3 million (2018 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was STC2818;E Fork RD over Big Wood River built?

It was built in 1974, making it 51 years old in 2025.

What condition is STC2818;E Fork RD over Big Wood River 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 September 2024.

How much traffic does STC2818;E Fork RD over Big Wood River carry?

About 2,800 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is STC2818;E Fork RD over Big Wood River?

The structure is 101 ft (30.8 m) long with a longest span of 98 ft (29.9 m) and a deck 32 ft wide.

Who owns STC2818;E Fork RD over Big Wood River?

It is owned by the County Highway Agency.