US Bridges

Sawmill Canyon RD over Little Lost River

Fair

Custer County, Idaho · 40.5 Mi. Nnw of Howe Id · Structure no. 040604000001118

Built
1957
68 years old, rebuilt 1997
Condition
Fair
inspected October 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
24 ft
1 main span
Daily traffic
40
1994 count
Owner
Federal
U.S. Forest Service

About this bridge

Sawmill Canyon RD over Little Lost River is a wood or timber stringer/multi-beam or girder carrying Sawmill Canyon RD over Little Lost River in Custer County, Idaho. It was built in 1957 and reconstructed in 1997, so it is 68 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.

It carries about 40 vehicles a day, projected to reach 50 by 2015. The structure is 24 ft (7.3 m) long and 15 ft wide. If it were closed, the detour would be 98.2 mi (158 km).

CarriesSawmill Canyon RD
CrossesLittle Lost River
Location40.5 Mi. Nnw of Howe Id
RouteFederal Lands Road 40101
StateIdaho
Coordinates44.31139, -113.3394
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionOctober 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 adequacy9: Superior to present desirable criteria
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating28.5 US tons
Inventory rating22.2 US tons

Structure

MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadHS 20
Structure length24 ft (7.3 m)
Longest span22 ft (6.7 m)
Deck width15 ft (4.6 m)
Roadway width14 ft (4.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic40 (1994)
Projected traffic50 by 2015
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.2 mi (158 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 Sawmill Canyon RD over Little Lost River built?

It was built in 1957, making it 68 years old in 2025. It was reconstructed in 1997.

What condition is Sawmill Canyon RD over Little Lost River 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 October 2024.

How much traffic does Sawmill Canyon RD over Little Lost River carry?

About 40 vehicles per day (1994 count).

How long is Sawmill Canyon RD over Little Lost River?

The structure is 24 ft (7.3 m) long with a longest span of 22 ft (6.7 m) and a deck 15 ft wide.

Who owns Sawmill Canyon RD over Little Lost River?

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