US Bridges

SH 39 Sbl over Snake R.;am.Falls Br.

Fair

Power County, Idaho · 0.7 W. American Falls · Structure no. 000000000014145

Built
1975
50 years old
Condition
Fair
inspected August 2024
Type
Girder and Floorbeam System
Steel Continuous
Length
1,144 ft
3 main spans
Daily traffic
2,900
2023 count
Owner
State
State Highway Agency

About this bridge

SH 39 Sbl over Snake R.;am.Falls Br. is a steel continuous girder and floorbeam system carrying SH 39 Sbl over Snake R.;am.Falls Br. in Power County, Idaho. It was built in 1975, so it is 50 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 2,900 vehicles a day, roughly 21% of them trucks, projected to reach 4,350 by 2042. The structure is 1,144 ft (348.7 m) long and 37 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesSH 39 Sbl
CrossesSnake R.;am.Falls Br.
Location0.7 W. American Falls
RouteState Highway 39
CountyPower County
StateIdaho
Coordinates42.77792, -112.87769
Functional classRural Minor Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection9 ExcellentNo problems noted.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating86 US tons
Inventory rating51 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3 (+6 approach)
Design loadHS 20
Structure length1,144 ft (348.7 m)
Longest span257 ft (78.3 m)
Deck width37 ft (11.4 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,900 (2023)
Projected traffic4,350 by 2042
Trucks21%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway and pedestrian
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 39 Sbl over Snake R.;am.Falls Br. built?

It was built in 1975, making it 50 years old in 2025.

What condition is SH 39 Sbl over Snake R.;am.Falls 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 SH 39 Sbl over Snake R.;am.Falls Br. carry?

About 2,900 vehicles per day (2023 count), of which roughly 21% are trucks.

How long is SH 39 Sbl over Snake R.;am.Falls Br.?

The structure is 1,144 ft (348.7 m) long with a longest span of 257 ft (78.3 m) and a deck 37 ft wide.

Who owns SH 39 Sbl over Snake R.;am.Falls Br.?

It is owned by the State Highway Agency.