US Bridges

Bohemian HWY over Russian River

Fair

Sonoma County, California · At Monte Rio · Structure no. 20C0018

Built
1934
91 years old
Condition
Fair
inspected November 2024
Type
Truss - Thru
Steel
Length
772 ft
5 main spans
Daily traffic
3,100
2015 count
Owner
County
County Highway Agency

About this bridge

Bohemian HWY over Russian River is a steel truss - thru carrying Bohemian HWY over Russian River in Sonoma County, California. It was built in 1934, so it is 91 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 3,100 vehicles a day, roughly 1% of them trucks, projected to reach 3,325 by 2042. The structure is 772 ft (235.3 m) long and 34 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

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CarriesBohemian HWY
CrossesRussian River
LocationAt Monte Rio
RouteCounty Highway 0
CountySonoma County
StateCalifornia
Coordinates38.46551, -123.00933
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionNovember 2024
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 geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating38.9 US tons
Inventory rating23.3 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckConcrete, cast-in-place
Main spans5 (+7 approach)
Design loadH 15
Structure length772 ft (235.3 m)
Longest span100 ft (30.5 m)
Deck width34 ft (10.4 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,100 (2015)
Projected traffic3,325 by 2042
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed6.8 mi (11 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 Bohemian HWY over Russian River built?

It was built in 1934, making it 91 years old in 2025.

What condition is Bohemian HWY over Russian 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 November 2024.

How much traffic does Bohemian HWY over Russian River carry?

About 3,100 vehicles per day (2015 count), of which roughly 1% are trucks.

How long is Bohemian HWY over Russian River?

The structure is 772 ft (235.3 m) long with a longest span of 100 ft (30.5 m) and a deck 34 ft wide.

Who owns Bohemian HWY over Russian River?

It is owned by the County Highway Agency.