US Bridges

Fs Route No. 320 over Heller-Sherlock Creek

Fair

Shoshone County, Idaho · Heller Sherlock CR · Structure no. 010402000000178

Built
1953
72 years old, rebuilt 2011
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
27 ft
1 main span
Daily traffic
50
Owner
Federal
U.S. Forest Service

About this bridge

Fs Route No. 320 over Heller-Sherlock Creek is a wood or timber stringer/multi-beam or girder carrying Fs Route No. 320 over Heller-Sherlock Creek in Shoshone County, Idaho. It was built in 1953 and reconstructed in 2011, so it is 72 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 50 vehicles a day, projected to reach 75 by 2045. The structure is 27 ft (8.1 m) long and 15 ft wide. If it were closed, the detour would be 620.7 mi (999 km).

Location

Open in Google Maps
CarriesFs Route No. 320
CrossesHeller-Sherlock Creek
LocationHeller Sherlock CR
RouteFederal Lands Road 320
CountyShoshone County
StateIdaho
Coordinates47.04344, -115.16427
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating23.6 US tons
Inventory rating18.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadH 20
Structure length27 ft (8.1 m)
Longest span25 ft (7.7 m)
Deck width15 ft (4.7 m)
Roadway width13 ft (4.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (—)
Projected traffic75 by 2045
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed620.7 mi (999 km)
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 Fs Route No. 320 over Heller-Sherlock Creek built?

It was built in 1953, making it 72 years old in 2025. It was reconstructed in 2011.

What condition is Fs Route No. 320 over Heller-Sherlock 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 July 2024.

How much traffic does Fs Route No. 320 over Heller-Sherlock Creek carry?

About 50 vehicles per day (latest count).

How long is Fs Route No. 320 over Heller-Sherlock Creek?

The structure is 27 ft (8.1 m) long with a longest span of 25 ft (7.7 m) and a deck 15 ft wide.

Who owns Fs Route No. 320 over Heller-Sherlock Creek?

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