US Bridges

STC3906;WARREN Wgn over Twenty Mile Creek

Good

Valley County, Idaho · 15.7 N. 4.0 E. Mccall · Structure no. 000000000020110

Built
1969
56 years old
Condition
Good
inspected August 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
102 ft
1 main span
Daily traffic
550
2023 count
Owner
County
County Highway Agency

About this bridge

STC3906;WARREN Wgn over Twenty Mile Creek is a prestressed concrete stringer/multi-beam or girder carrying STC3906;WARREN Wgn over Twenty Mile Creek in Valley County, Idaho. It was built in 1969, so it is 56 years old, older than the Idaho average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 550 vehicles a day, roughly 2% of them trucks, projected to reach 825 by 2042. The structure is 102 ft (31.1 m) long and 31 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

CarriesSTC3906;WARREN Wgn
CrossesTwenty Mile Creek
Location15.7 N. 4.0 E. Mccall
RouteCounty Highway 3906
StateIdaho
Coordinates45.13094, -116.01481
Functional classRural Major Collector

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating63.1 US tons
Inventory rating38 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length102 ft (31.1 m)
Longest span100 ft (30.5 m)
Deck width31 ft (9.5 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic550 (2023)
Projected traffic825 by 2042
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was STC3906;WARREN Wgn over Twenty Mile Creek built?

It was built in 1969, making it 56 years old in 2025.

What condition is STC3906;WARREN Wgn over Twenty Mile Creek in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in August 2024.

How much traffic does STC3906;WARREN Wgn over Twenty Mile Creek carry?

About 550 vehicles per day (2023 count), of which roughly 2% are trucks.

How long is STC3906;WARREN Wgn over Twenty Mile Creek?

The structure is 102 ft (31.1 m) long with a longest span of 100 ft (30.5 m) and a deck 31 ft wide.

Who owns STC3906;WARREN Wgn over Twenty Mile Creek?

It is owned by the County Highway Agency.