US Bridges

Stc 4721; S River over Cottonwood Creek

FairPosted for load

Idaho County, Idaho · 0.7 S. 0.2 W. Stites · Structure no. 000000000029240

Built
1964
61 years old
Condition
Fair
inspected September 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
130 ft
2 main spans
Daily traffic
430
2023 count
Owner
County
County Highway Agency

About this bridge

Stc 4721; S River over Cottonwood Creek is a steel stringer/multi-beam or girder carrying Stc 4721; S River over Cottonwood Creek in Idaho County, Idaho. It was built in 1964, so it is 61 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 430 vehicles a day, roughly 8% of them trucks, projected to reach 645 by 2042. The structure is 130 ft (39.6 m) long and 18 ft wide. If it were closed, the detour would be 49.7 mi (80 km).

Location

Open in Google Maps
CarriesStc 4721; S River
CrossesCottonwood Creek
Location0.7 S. 0.2 W. Stites
RouteCounty Highway 4721
CountyIdaho County
StateIdaho
Coordinates46.0805, -115.97872
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating35.1 US tons
Inventory rating20 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckCorrugated steel
Main spans2
Design loadHS 20
Structure length130 ft (39.6 m)
Longest span63 ft (19.2 m)
Deck width18 ft (5.4 m)
Roadway width17 ft (5.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic430 (2023)
Projected traffic645 by 2042
Trucks8%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed49.7 mi (80 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$1.2 million (2019 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Stc 4721; S River over Cottonwood Creek built?

It was built in 1964, making it 61 years old in 2025.

What condition is Stc 4721; S River over Cottonwood 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 September 2023.

How much traffic does Stc 4721; S River over Cottonwood Creek carry?

About 430 vehicles per day (2023 count), of which roughly 8% are trucks.

How long is Stc 4721; S River over Cottonwood Creek?

The structure is 130 ft (39.6 m) long with a longest span of 63 ft (19.2 m) and a deck 18 ft wide.

Who owns Stc 4721; S River over Cottonwood Creek?

It is owned by the County Highway Agency.