US Bridges

Sq___ Creek Road over Jackknife Creek

Fair

Bonneville County, Idaho · No Data Entered · Structure no. 040502000001010

Built
1963
62 years old
Condition
Fair
inspected August 2021
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
30 ft
1 main span
Daily traffic
20
Owner
Federal
U.S. Forest Service

About this bridge

Sq___ Creek Road over Jackknife Creek is a wood or timber stringer/multi-beam or girder carrying Sq___ Creek Road over Jackknife Creek in Bonneville County, Idaho. It was built in 1963, so it is 62 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 20 vehicles a day, projected to reach 30 by 2045. The structure is 30 ft (9.1 m) long and 16 ft wide.

Location

Open in Google Maps
CarriesSq___ Creek Road
CrossesJackknife Creek
LocationNo Data Entered
RouteCounty Highway 20389
CountyBonneville County
StateIdaho
Coordinates43.04898, -111.11091
Functional classRural Local

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 protection7 GoodSome minor problems.
Last inspectionAugust 2021
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating31.7 US tons
Inventory rating24.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadHS 20
Structure length30 ft (9.1 m)
Longest span28 ft (8.5 m)
Deck width16 ft (4.9 m)
Roadway width15 ft (4.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic20 (—)
Projected traffic30 by 2045
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed—
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerU.S. Forest Service
Maintained byU.S. Forest Service
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Sq___ Creek Road over Jackknife Creek built?

It was built in 1963, making it 62 years old in 2025.

What condition is Sq___ Creek Road over Jackknife 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 August 2021.

How much traffic does Sq___ Creek Road over Jackknife Creek carry?

About 20 vehicles per day (latest count).

How long is Sq___ Creek Road over Jackknife Creek?

The structure is 30 ft (9.1 m) long with a longest span of 28 ft (8.5 m) and a deck 16 ft wide.

Who owns Sq___ Creek Road over Jackknife Creek?

It is owned by the U.S. Forest Service.