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Bridge conditions in Sonoma County, California

611 inventoried bridges · 32 rated poor · 2025 National Bridge Inventory

United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled August 20, 2026

The federal inventory lists 611 bridges in Sonoma County: 138 rated good, 441 fair, and 32 poor.

32 of the 611 bridges in Sonoma County, California, are rated in poor condition (5.2%) in the 2025 National Bridge Inventory, as of August 20, 2026.
138 bridges (22.6%) are rated good and 441 (72.2%) fair.
The median Sonoma County bridge was built in 1967.
The busiest poor-rated bridge is US Highway 101 over Dry Creek Road (built 1960), carrying about 45,500 vehicles a day.

Good 22.6% · Fair 72.2% · Poor 5.2% of 611 bridges

Bridges rated poor

Every bridge in the county with a poor rating, busiest first. Poor means a major component is rated 4 or lower on FHWA's 0-9 scale; it is a repair flag, not a closure notice.

Bridge	Built	Vehicles/day	Condition
US Highway 101 over Dry Creek Road	1960	45,500	Poor
U.S. Highway 101 over Westside Rd	1960	45,500	Poor
US Highway 101 SB over Chiquita Road	1960	22,500	Poor
Washington St over Petaluma River	1970	21,900	Poor
Old Redwood Hwy over Willow Brook Creek	1999	19,980	Poor
Arnold Drive over Sonoma Creek	1930	13,900	Poor
Arnold Dr over Sonoma Creek	1924	13,900	Poor
State Route 116 over Green Valley Creek	1930	12,400	Poor
River Rd over Russian River	1914	10,000	Poor
Old Redwood Hwy over Laguna De Santa Rosa	1956	9,800	Poor
River Rd over Mark West Creek	1958	8,000	Poor
US Highway 101 NB over First St & Cloverdale CR	1994	6,800	Poor
Windsor Road over Pool Creek	1967	5,900	Poor
Tomales Rd over Stemple Creek	1970	3,000	Poor
Green Valley Rd over Atascadero Creek	1967	2,500	Poor
Wilfred Ave over Belview-wilfred Creek	1963	1,857	Poor
Llano Rd over Colgan Creek	1979	1,750	Poor
8TH St East over Schell Creek	1968	1,500	Poor
Sartori Dr over Adobe Creek	1976	1,475	Poor
Mill Station Rd over Atascadero CR Overflow	1964	1,450	Poor
Main St over Dutch Bill Creek	1953	838	Poor
Bloomfield Rd over Bloomfield Creek	1917	524	Poor
Franz Valey Sch Rd over Franz Creek	1946	350	Poor
Fir Road over Dutch Bill Creek	1974	300	Poor
Mill Creek Rd over Mill Creek	1961	210	Poor
Seavey Rd over No Name Creek	1960	200	Poor
Sweetwtr Sprngs Rd over Porter Creek	1968	140	Poor
Gericke Rd over Americano Creek	1972	100	Poor
Eagle Nest Lane over Hillside	1930	100	Poor
Pine Flat Rd over Sausal Creek	1974	100	Poor
Geysers Road over Camacho Creek	1974	60	Poor
Old Duncans Grd Rd over Austin Creek	1924	30	Poor

Busiest bridges in the county

Bridge	Built	Vehicles/day	Condition
US Highway 101 over College Avenue	2009	136,500	Fair
U.S. Route 101 over Future Rainier Avenue	2022	103,000	Fair
US Highway 101 over 3RD St 4TH St & 5TH St	1968	96,000	Fair
US Highway 101 over Ninth Street	1968	96,000	Fair
U.S. Highway 101 over Santa Rosa Creek	2009	96,000	Fair
U.S. Highway 101 over Sixth Street	2009	96,000	Fair
US Highway 101 over Steele Lane	2009	96,000	Fair
US Highway 101 NB over Willow Brook	1956	94,000	Fair
US Highway 101 over Corona Ditch	1954	94,000	Good
US Highway 101 over Copeland Creek	1956	92,000	Fair

Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.

Every bridge in Sonoma County → - all 611, busiest first, each with its own condition record.

All of California: California bridge conditions by county · every download on the data page.

Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.