US Bridges

Marshall-Petaluma over Salmon Creek

Fair

Marin County, California · 0.3M W of Hicksvalley RD · Structure no. 27C0110

Built
1928
97 years old
Condition
Fair
inspected July 2024
Type
Tee Beam
Concrete
Length
22 ft
1 main span
Daily traffic
328
1973 count
Owner
County
County Highway Agency

About this bridge

Marshall-Petaluma over Salmon Creek is a concrete tee beam carrying Marshall-Petaluma over Salmon Creek in Marin County, California. It was built in 1928, so it is 97 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 6 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 328 vehicles a day, roughly 2% of them trucks, projected to reach 498 by 2046. The structure is 22 ft (6.7 m) long and 26 ft wide. If it were closed, the detour would be 29.8 mi (48 km).

Location

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CarriesMarshall-Petaluma
CrossesSalmon Creek
Location0.3M W of Hicksvalley RD
RouteCounty Highway 0
CountyMarin County
StateCalifornia
Coordinates38.16543, -122.73635
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating30.3 US tons
Inventory rating23.6 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length22 ft (6.7 m)
Longest span21 ft (6.4 m)
Deck width26 ft (7.9 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic328 (1973)
Projected traffic498 by 2046
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed29.8 mi (48 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 Marshall-Petaluma over Salmon Creek built?

It was built in 1928, making it 97 years old in 2025.

What condition is Marshall-Petaluma over Salmon 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 July 2024.

How much traffic does Marshall-Petaluma over Salmon Creek carry?

About 328 vehicles per day (1973 count), of which roughly 2% are trucks.

How long is Marshall-Petaluma over Salmon Creek?

The structure is 22 ft (6.7 m) long with a longest span of 21 ft (6.4 m) and a deck 26 ft wide.

Who owns Marshall-Petaluma over Salmon Creek?

It is owned by the County Highway Agency.