US Bridges

State Route 12 over N. Fork Calaveras River

Fair

Calaveras County, California · 10-CAL-012-17.25 · Structure no. 30 0007

Built
1938
87 years old
Condition
Fair
inspected May 2023
Type
Tee Beam
Concrete Continuous
Length
300 ft
6 main spans
Daily traffic
7,000
2019 count
Owner
State
State Highway Agency

About this bridge

State Route 12 over N. Fork Calaveras River is a concrete continuous tee beam carrying State Route 12 over N. Fork Calaveras River in Calaveras County, California. It was built in 1938, so it is 87 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 7,000 vehicles a day, roughly 7% of them trucks, projected to reach 18,334 by 2041. The structure is 300 ft (91.4 m) long and 33 ft wide. If it were closed, the detour would be 11.2 mi (18 km).

Location

Open in Google Maps
CarriesState Route 12
CrossesN. Fork Calaveras River
Location10-CAL-012-17.25
RouteState Highway 12
CountyCalaveras County
StateCalifornia
Coordinates38.20631, -120.71128
Functional classRural Minor Arterial

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 protection8 Very GoodNo problems noted.
Last inspectionMay 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 geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating31.4 US tons
Inventory rating22.2 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans6
Design loadH 15
Structure length300 ft (91.4 m)
Longest span64 ft (19.5 m)
Deck width33 ft (10 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,000 (2019)
Projected traffic18,334 by 2041
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.2 mi (18 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 State Route 12 over N. Fork Calaveras River built?

It was built in 1938, making it 87 years old in 2025.

What condition is State Route 12 over N. Fork Calaveras River 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 May 2023.

How much traffic does State Route 12 over N. Fork Calaveras River carry?

About 7,000 vehicles per day (2019 count), of which roughly 7% are trucks.

How long is State Route 12 over N. Fork Calaveras River?

The structure is 300 ft (91.4 m) long with a longest span of 64 ft (19.5 m) and a deck 33 ft wide.

Who owns State Route 12 over N. Fork Calaveras River?

It is owned by the State Highway Agency.