US Bridges

Elk Prairie Road over ST Joe River;calder Br.

Fair

Shoshone County, Idaho · 0.1 S. Calder · Structure no. 000000000030730

Built
1990
35 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
296 ft
3 main spans
Daily traffic
160
2023 count
Owner
County
County Highway Agency

About this bridge

Elk Prairie Road over ST Joe River;calder Br. is a prestressed concrete stringer/multi-beam or girder carrying Elk Prairie Road over ST Joe River;calder Br. in Shoshone County, Idaho. It was built in 1990, so it is 35 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 160 vehicles a day, roughly 7% of them trucks, projected to reach 240 by 2039. The structure is 296 ft (90.2 m) long and 30 ft wide. If it were closed, the detour would be 19.3 mi (31 km).

Location

Open in Google Maps
CarriesElk Prairie Road
CrossesST Joe River;calder Br.
Location0.1 S. Calder
RouteCounty Highway 0
CountyShoshone County
StateIdaho
Coordinates47.27392, -116.18866
Functional classRural Minor 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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating71 US tons
Inventory rating25.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 25 or greater
Structure length296 ft (90.2 m)
Longest span98 ft (29.9 m)
Deck width30 ft (9.1 m)
Roadway width28 ft (8.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic160 (2023)
Projected traffic240 by 2039
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed19.3 mi (31 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Elk Prairie Road over ST Joe River;calder Br. built?

It was built in 1990, making it 35 years old in 2025.

What condition is Elk Prairie Road over ST Joe River;calder Br. 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 Elk Prairie Road over ST Joe River;calder Br. carry?

About 160 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is Elk Prairie Road over ST Joe River;calder Br.?

The structure is 296 ft (90.2 m) long with a longest span of 98 ft (29.9 m) and a deck 30 ft wide.

Who owns Elk Prairie Road over ST Joe River;calder Br.?

It is owned by the County Highway Agency.