US Bridges

Cannibal Road over Mosley Slough

Fair

Humboldt County, California · 3.7 MI W of Eel River Dr. · Structure no. 04C0038

Built
1959
66 years old, rebuilt 1965
Condition
Fair
inspected August 2024
Type
Tee Beam
Concrete Continuous
Length
296 ft
2 main spans
Daily traffic
434
2015 count
Owner
County
County Highway Agency

About this bridge

Cannibal Road over Mosley Slough is a concrete continuous tee beam carrying Cannibal Road over Mosley Slough in Humboldt County, California. It was built in 1959 and reconstructed in 1965, so it is 66 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 434 vehicles a day, roughly 3% of them trucks, projected to reach 1,400 by 2042. The structure is 296 ft (90.3 m) long and 25 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesCannibal Road
CrossesMosley Slough
Location3.7 MI W of Eel River Dr.
RouteCounty Highway 0
CountyHumboldt County
StateCalifornia
Coordinates40.64316, -124.29661
Functional classRural Minor 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.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2024
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 geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating60.4 US tons
Inventory rating36 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2 (+8 approach)
Design loadUnknown
Structure length296 ft (90.3 m)
Longest span58 ft (17.7 m)
Deck width25 ft (7.5 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic434 (2015)
Projected traffic1,400 by 2042
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 Cannibal Road over Mosley Slough built?

It was built in 1959, making it 66 years old in 2025. It was reconstructed in 1965.

What condition is Cannibal Road over Mosley 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 August 2024.

How much traffic does Cannibal Road over Mosley Slough carry?

About 434 vehicles per day (2015 count), of which roughly 3% are trucks.

How long is Cannibal Road over Mosley Slough?

The structure is 296 ft (90.3 m) long with a longest span of 58 ft (17.7 m) and a deck 25 ft wide.

Who owns Cannibal Road over Mosley Slough?

It is owned by the County Highway Agency.