US Bridges

Mattole RD over Dry Creek

Fair

Humboldt County, California · 1 MI S/O Singley Creek · Structure no. 04C0241

Built
1985
40 years old, rebuilt 2013
Condition
Fair
inspected March 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
89 ft
1 main span
Daily traffic
196
2011 count
Owner
County
County Highway Agency

About this bridge

Mattole RD over Dry Creek is a steel stringer/multi-beam or girder carrying Mattole RD over Dry Creek in Humboldt County, California. It was built in 1985 and reconstructed in 2013, so it is 40 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 196 vehicles a day, roughly 8% of them trucks, projected to reach 327 by 2042. The structure is 89 ft (27.1 m) long and 18 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

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CarriesMattole RD
CrossesDry Creek
Location1 MI S/O Singley Creek
RouteCounty Highway 0
CountyHumboldt County
StateCalifornia
Coordinates40.41741, -124.39796
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
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 inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
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 adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating32.5 US tons
Inventory rating21.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckSteel plate
Main spans1
Design loadUnknown
Structure length89 ft (27.1 m)
Longest span84 ft (25.6 m)
Deck width18 ft (5.5 m)
Roadway width14 ft (4.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic196 (2011)
Projected traffic327 by 2042
Trucks8%
Lanes on structure1
Traffic directionOne-lane bridge for two-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 Mattole RD over Dry Creek built?

It was built in 1985, making it 40 years old in 2025. It was reconstructed in 2013.

What condition is Mattole RD over 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 March 2024.

How much traffic does Mattole RD over Dry Creek carry?

About 196 vehicles per day (2011 count), of which roughly 8% are trucks.

How long is Mattole RD over Dry Creek?

The structure is 89 ft (27.1 m) long with a longest span of 84 ft (25.6 m) and a deck 18 ft wide.

Who owns Mattole RD over Dry Creek?

It is owned by the County Highway Agency.