US Bridges

Obyrnes Ferry RD over Black Creek

Fair

Calaveras County, California · 2.0 MI S Intx With SR 4 · Structure no. 30C0028

Built
1972
53 years old
Condition
Fair
inspected February 2025
Type
Tee Beam
Concrete Continuous
Length
120 ft
3 main spans
Daily traffic
3,082
2007 count
Owner
County
County Highway Agency

About this bridge

Obyrnes Ferry RD over Black Creek is a concrete continuous tee beam carrying Obyrnes Ferry RD over Black Creek in Calaveras County, California. It was built in 1972, so it is 53 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 3,082 vehicles a day, roughly 1% of them trucks, projected to reach 7,684 by 2043. The structure is 120 ft (36.6 m) long and 29 ft wide. If it were closed, the detour would be 49.7 mi (80 km).

Location

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CarriesObyrnes Ferry RD
CrossesBlack Creek
Location2.0 MI S Intx With SR 4
RouteCounty Highway 0
CountyCalaveras County
StateCalifornia
Coordinates37.96086, -120.61524
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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionFebruary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating58.5 US tons
Inventory rating45 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 20
Structure length120 ft (36.6 m)
Longest span48 ft (14.6 m)
Deck width29 ft (8.7 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,082 (2007)
Projected traffic7,684 by 2043
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed49.7 mi (80 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 Obyrnes Ferry RD over Black Creek built?

It was built in 1972, making it 53 years old in 2025.

What condition is Obyrnes Ferry RD over Black 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 February 2025.

How much traffic does Obyrnes Ferry RD over Black Creek carry?

About 3,082 vehicles per day (2007 count), of which roughly 1% are trucks.

How long is Obyrnes Ferry RD over Black Creek?

The structure is 120 ft (36.6 m) long with a longest span of 48 ft (14.6 m) and a deck 29 ft wide.

Who owns Obyrnes Ferry RD over Black Creek?

It is owned by the County Highway Agency.