US Bridges

Mattole Road over Little Dry Creek

Fair

Humboldt County, California · 7.6 MI NW of Petrolia · Structure no. 04C0265

Built
2018
7 years old
Condition
Fair
inspected June 2024
Type
Girder and Floorbeam System
Steel
Length
81 ft
1 main span
Daily traffic
200
2024 count
Owner
County
County Highway Agency

About this bridge

Mattole Road over Little Dry Creek is a steel girder and floorbeam system carrying Mattole Road over Little Dry Creek in Humboldt County, California. It was built in 2018, so it is 7 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 200 vehicles a day, roughly 3% of them trucks, projected to reach 260 by 2044. The structure is 81 ft (24.7 m) long and 21 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesMattole Road
CrossesLittle Dry Creek
Location7.6 MI NW of Petrolia
RouteCounty Highway 0
CountyHumboldt County
StateCalifornia
Coordinates40.39081, -124.37057
Functional classRural Major 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
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure8 Very GoodNo problems noted.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59.5 US tons
Inventory rating35.7 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel
DeckSteel plate
Main spans1
Design loadUnknown
Structure length81 ft (24.7 m)
Longest span74 ft (22.7 m)
Deck width21 ft (6.3 m)
Roadway width19 ft (5.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic200 (2024)
Projected traffic260 by 2044
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Mattole Road over Little Dry Creek built?

It was built in 2018, making it 7 years old in 2025.

What condition is Mattole Road over Little Dry 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 June 2024.

How much traffic does Mattole Road over Little Dry Creek carry?

About 200 vehicles per day (2024 count), of which roughly 3% are trucks.

How long is Mattole Road over Little Dry Creek?

The structure is 81 ft (24.7 m) long with a longest span of 74 ft (22.7 m) and a deck 21 ft wide.

Who owns Mattole Road over Little Dry Creek?

It is owned by the County Highway Agency.