US Bridges

Horse Creek Road over Seiad Creek

Fair

Siskiyou County, California · Horse · Structure no. 050551000001039

Built
1956
69 years old
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
62 ft
1 main span
Daily traffic
50
Owner
Federal
U.S. Forest Service

About this bridge

Horse Creek Road over Seiad Creek is a steel stringer/multi-beam or girder carrying Horse Creek Road over Seiad Creek in Siskiyou County, California. It was built in 1956, so it is 69 years old, older than the California average of 54.8 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 50 vehicles a day, projected to reach 75 by 2045. The structure is 62 ft (18.9 m) long and 17 ft wide.

Location

Open in Google Maps
CarriesHorse Creek Road
CrossesSeiad Creek
LocationHorse
RouteFederal Lands Road 46N50
CountySiskiyou County
StateCalifornia
Coordinates41.8644, -123.14276
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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionSeptember 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 geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating29.3 US tons
Inventory rating22.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length62 ft (18.9 m)
Longest span59 ft (18 m)
Deck width17 ft (5.1 m)
Roadway width15 ft (4.5 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 closed—
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 Horse Creek Road over Seiad Creek built?

It was built in 1956, making it 69 years old in 2025.

What condition is Horse Creek Road over Seiad 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 2024.

How much traffic does Horse Creek Road over Seiad Creek carry?

About 50 vehicles per day (latest count).

How long is Horse Creek Road over Seiad Creek?

The structure is 62 ft (18.9 m) long with a longest span of 59 ft (18 m) and a deck 17 ft wide.

Who owns Horse Creek Road over Seiad Creek?

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