US Bridges

Grayback Road over Indian Creek

Fair

Siskiyou County, California · Indian · Structure no. 050552000001018

Built
1965
60 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Concrete
Length
175 ft
2 main spans
Daily traffic
50
Owner
Federal
U.S. Forest Service

About this bridge

Grayback Road over Indian Creek is a concrete stringer/multi-beam or girder carrying Grayback Road over Indian Creek in Siskiyou County, California. It was built in 1965, so it is 60 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 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 175 ft (53.3 m) long and 31 ft wide.

Location

Open in Google Maps
CarriesGrayback Road
CrossesIndian Creek
LocationIndian
RouteFederal Lands Road 48
CountySiskiyou County
StateCalifornia
Coordinates41.91642, -123.46659
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry7: Better than present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating10.7 US tons
Inventory rating7.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialConcrete
DeckConcrete, cast-in-place
Main spans2 (+2 approach)
Design loadHS 20
Structure length175 ft (53.3 m)
Longest span64 ft (19.5 m)
Deck width31 ft (9.6 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (—)
Projected traffic75 by 2045
Trucks—
Lanes on structure2
Traffic directionTwo-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 Grayback Road over Indian Creek built?

It was built in 1965, making it 60 years old in 2025.

What condition is Grayback Road over Indian 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 August 2023.

How much traffic does Grayback Road over Indian Creek carry?

About 50 vehicles per day (latest count).

How long is Grayback Road over Indian Creek?

The structure is 175 ft (53.3 m) long with a longest span of 64 ft (19.5 m) and a deck 31 ft wide.

Who owns Grayback Road over Indian Creek?

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