US Bridges

State Route 120 over South Fork Tuolumne Riv

Good

Tuolumne County, California · 10-TUO-120-46.82 · Structure no. 32 0035

Built
1962
63 years old, rebuilt 1999
Condition
Good
inspected September 2023
Type
Girder and Floorbeam System
Steel Continuous
Length
577 ft
3 main spans
Daily traffic
3,650
2009 count
Owner
State
State Highway Agency

About this bridge

State Route 120 over South Fork Tuolumne Riv is a steel continuous girder and floorbeam system carrying State Route 120 over South Fork Tuolumne Riv in Tuolumne County, California. It was built in 1962 and reconstructed in 1999, so it is 63 years old, older than the California average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 3,650 vehicles a day, projected to reach 3,186 by 2045. The structure is 577 ft (175.9 m) long and 34 ft wide. If it were closed, the detour would be 44.7 mi (72 km).

Location

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CarriesState Route 120
CrossesSouth Fork Tuolumne Riv
Location10-TUO-120-46.82
RouteState Highway 120
CountyTuolumne County
StateCalifornia
Coordinates37.82291, -120.01414
Functional classRural Principal Arterial - Other

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating54.2 US tons
Inventory rating32.5 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3 (+2 approach)
Design loadH 20
Structure length577 ft (175.9 m)
Longest span212 ft (64.6 m)
Deck width34 ft (10.5 m)
Roadway width31 ft (9.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,650 (2009)
Projected traffic3,186 by 2045
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed44.7 mi (72 km)
TollOn a free road
National Highway SystemYes

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 120 over South Fork Tuolumne Riv built?

It was built in 1962, making it 63 years old in 2025. It was reconstructed in 1999.

What condition is State Route 120 over South Fork Tuolumne Riv in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in September 2023.

How much traffic does State Route 120 over South Fork Tuolumne Riv carry?

About 3,650 vehicles per day (2009 count).

How long is State Route 120 over South Fork Tuolumne Riv?

The structure is 577 ft (175.9 m) long with a longest span of 212 ft (64.6 m) and a deck 34 ft wide.

Who owns State Route 120 over South Fork Tuolumne Riv?

It is owned by the State Highway Agency.