US Bridges

Stc 6785;DIGGER DR over Teton Island Canal

FairPosted for load

Madison County, Idaho · 0.4 S. 0.5 E. Sugar City · Structure no. 000000000032795

Built
1959
66 years old, rebuilt 1989
Condition
Fair
inspected March 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
26 ft
1 main span
Daily traffic
710
2023 count
Owner
County
County Highway Agency

About this bridge

Stc 6785;DIGGER DR over Teton Island Canal is a steel stringer/multi-beam or girder carrying Stc 6785;DIGGER DR over Teton Island Canal in Madison County, Idaho. It was built in 1959 and reconstructed in 1989, so it is 66 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 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. Its operating status is: posted for load restriction.

It carries about 710 vehicles a day, projected to reach 1,065 by 2042. The structure is 26 ft (7.9 m) long and 49 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesStc 6785;DIGGER DR
CrossesTeton Island Canal
Location0.4 S. 0.5 E. Sugar City
RouteCounty Highway 6785
StateIdaho
Coordinates43.86908, -111.73797
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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating25 US tons
Inventory rating15 US tons

Structure

MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length26 ft (7.9 m)
Longest span23 ft (7 m)
Deck width49 ft (15 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic710 (2023)
Projected traffic1,065 by 2042
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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$558,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Stc 6785;DIGGER DR over Teton Island Canal built?

It was built in 1959, making it 66 years old in 2025. It was reconstructed in 1989.

What condition is Stc 6785;DIGGER DR over Teton Island Canal 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 March 2023.

How much traffic does Stc 6785;DIGGER DR over Teton Island Canal carry?

About 710 vehicles per day (2023 count).

How long is Stc 6785;DIGGER DR over Teton Island Canal?

The structure is 26 ft (7.9 m) long with a longest span of 23 ft (7 m) and a deck 49 ft wide.

Who owns Stc 6785;DIGGER DR over Teton Island Canal?

It is owned by the County Highway Agency.