US Bridges

Ishi Pishi Road over Wilson Creek

Fair

Humboldt County, California · 3.1 MI S JCT With SR 96 · Structure no. 04C0223

Built
1975
50 years old
Condition
Fair
inspected October 2023
Type
Box Beam or Girders - Multiple
Concrete
Length
57 ft
1 main span
Daily traffic
132
2011 count
Owner
County
County Highway Agency

About this bridge

Ishi Pishi Road over Wilson Creek is a concrete box beam or girders - multiple carrying Ishi Pishi Road over Wilson Creek in Humboldt County, California. It was built in 1975, so it is 50 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 132 vehicles a day, roughly 1% of them trucks, projected to reach 154 by 2041. The structure is 57 ft (17.4 m) long and 17 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

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CarriesIshi Pishi Road
CrossesWilson Creek
Location3.1 MI S JCT With SR 96
RouteCounty Highway 0
CountyHumboldt County
StateCalifornia
Coordinates41.33774, -123.52024
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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionOctober 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 geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating42.1 US tons
Inventory rating32.5 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length57 ft (17.4 m)
Longest span52 ft (15.8 m)
Deck width17 ft (5.3 m)
Roadway width17 ft (5.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic132 (2011)
Projected traffic154 by 2041
Trucks1%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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 Ishi Pishi Road over Wilson Creek built?

It was built in 1975, making it 50 years old in 2025.

What condition is Ishi Pishi Road over Wilson 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 October 2023.

How much traffic does Ishi Pishi Road over Wilson Creek carry?

About 132 vehicles per day (2011 count), of which roughly 1% are trucks.

How long is Ishi Pishi Road over Wilson Creek?

The structure is 57 ft (17.4 m) long with a longest span of 52 ft (15.8 m) and a deck 17 ft wide.

Who owns Ishi Pishi Road over Wilson Creek?

It is owned by the County Highway Agency.