US Bridges

King Salmon DR over King Salmon Slough

Fair

Humboldt County, California · 1/4 MI NW of SR 101 · Structure no. 04C0230

Built
1988
37 years old
Condition
Fair
inspected June 2023
Type
Slab
Concrete Continuous
Length
103 ft
5 main spans
Daily traffic
1,782
2009 count
Owner
County
County Highway Agency

About this bridge

King Salmon DR over King Salmon Slough is a concrete continuous slab carrying King Salmon DR over King Salmon Slough in Humboldt County, California. It was built in 1988, so it is 37 years old, younger 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 1,782 vehicles a day, roughly 3% of them trucks, projected to reach 6,984 by 2043. The structure is 103 ft (31.4 m) long and 35 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesKing Salmon DR
CrossesKing Salmon Slough
Location1/4 MI NW of SR 101
RouteCounty Highway 0
CountyHumboldt County
StateCalifornia
Coordinates40.73877, -124.21266
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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
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 alignment7: Better than present minimum criteria
Operating rating59.6 US tons
Inventory rating35.7 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20 + Mod
Structure length103 ft (31.4 m)
Longest span20 ft (6.1 m)
Deck width35 ft (10.8 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,782 (2009)
Projected traffic6,984 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was King Salmon DR over King Salmon Slough built?

It was built in 1988, making it 37 years old in 2025.

What condition is King Salmon DR over King Salmon Slough 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 June 2023.

How much traffic does King Salmon DR over King Salmon Slough carry?

About 1,782 vehicles per day (2009 count), of which roughly 3% are trucks.

How long is King Salmon DR over King Salmon Slough?

The structure is 103 ft (31.4 m) long with a longest span of 20 ft (6.1 m) and a deck 35 ft wide.

Who owns King Salmon DR over King Salmon Slough?

It is owned by the County Highway Agency.