US Bridges

SH 75 over Big Wood River

Good

Blaine County, Idaho · 6.2 S. Ketchum · Structure no. 000000000017666

Built
2002
23 years old
Condition
Good
inspected July 2022
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
184 ft
2 main spans
Daily traffic
14,500
2023 count
Owner
State
State Highway Agency

About this bridge

SH 75 over Big Wood River is a prestressed concrete stringer/multi-beam or girder carrying SH 75 over Big Wood River in Blaine County, Idaho. It was built in 2002, so it is 23 years old, younger than the Idaho average of 45.3 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 14,500 vehicles a day, roughly 7% of them trucks, projected to reach 21,750 by 2042. The structure is 184 ft (56.1 m) long and 63 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesSH 75
CrossesBig Wood River
Location6.2 S. Ketchum
RouteState Highway 75
CountyBlaine County
StateIdaho
Coordinates43.59719, -114.34653
Functional classRural Minor Arterial

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.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation8: Equal to present desirable criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating110.1 US tons
Inventory rating53 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans2
Design loadHS 25 or greater
Structure length184 ft (56.1 m)
Longest span87 ft (26.5 m)
Deck width63 ft (19.2 m)
Roadway width60 ft (18.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic14,500 (2023)
Projected traffic21,750 by 2042
Trucks7%
Lanes on structure3
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$3.9 million
NavigationNo navigation control on waterway

Frequently asked questions

When was SH 75 over Big Wood River built?

It was built in 2002, making it 23 years old in 2025.

What condition is SH 75 over Big Wood River 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 July 2022.

How much traffic does SH 75 over Big Wood River carry?

About 14,500 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is SH 75 over Big Wood River?

The structure is 184 ft (56.1 m) long with a longest span of 87 ft (26.5 m) and a deck 63 ft wide.

Who owns SH 75 over Big Wood River?

It is owned by the State Highway Agency.