Marin County, CA

217 public highway bridges

Marin County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Marin County, California contains 217 public highway bridges. Roughly 34.6% are rated “Good,” 35% “Fair,” and 8.3% “Poor.” Poor means the lowest applicable deck, superstructure, substructure, or culvert rating is 4 or below on the 0–9 NBI scale. It is a condition category, not a live safety or closure decision.

Responsible agencies inspect covered bridges on risk-based intervals under current NBIS rules and submit inventory data to FHWA annually. The list below shows every NBI-tracked bridge in the county. Use the “Sort by” controls to change the ordering, and click any row for its reported inspection date, traffic count, and condition fields.

Source: FHWA National Bridge Inventory. See methodology for full definitions.

217
Total Bridges
34.6%
Good
35%
Fair
8.3%
Poor Condition

Condition Distribution

Good
34.6% (75)
Fair
35% (76)
Poor
8.3% (18)

All Bridges (217)

STATE ROUTE 37 WB

Fair

Over: NOVATO CREEK

04-MRN-037-11.96-NVTO, Marin, CA

Built 1959 Load: 32.4 t ADT: 17,000

STATE ROUTE 37 EB

Fair

Over: NOVATO CREEK

04-MRN-037-11.96-NVTO, Marin, CA

Built 1959 Load: 32.4 t ADT: 17,000

STATE ROUTE 37

Fair

Over: SIMONDS SLOUGH

04-MRN-037-13.04-NVTO, Marin, CA

Built 1959 Load: 32.4 t ADT: 34,000

STATE ROUTE 37

Fair

Over: PETALUMA RIVER

04-MRN-037-14.47, Marin, CA

Built 1958 Load: 32.4 t ADT: 34,000

US HIGHWAY 101

Fair

Over: NORTH SAN PEDRO ROAD

04-MRN-101-12.69-SRF, Marin, CA

Built 1979 Load: 32.4 t ADT: 180,000

U.S. HIGHWAY 101

Fair

Over: FRANKLIN AV & NWP RR

04-MRN-101-R20.89-NVTO, Marin, CA

Built 1974 Load: 32.4 t ADT: 61,500

State Route 1

Fair

Over: MILLERTON GULCH

04-MRN-001-33.40, Marin, CA

Built 1997 Load: 32.4 t ADT: 2,300

OLEMA-BOLINAS RD

Fair

Over: PINE GULCH CREEK

1.3 MI S OF SR 1, Marin, CA

Built 1986 Load: 32.4 t ADT: 2,076

ALEXANDER RD

Fair

Over: STEMPLE CREEK

0.39 MI N TMALS-PETLMA RD, Marin, CA

Built 1962 Load: 32.4 t ADT: 60

MOUNT LASSEN DR NB

Fair

Over: MILLER CREEK

0.06 MI N LUCAS VALLEY RD, Marin, CA

Built 1965 Load: 32.4 t ADT: 980

CANYON ROAD

Fair

Over: SAN ANSELMO CREEK

0.1 MI S/O CASCADE DR, Marin, CA

Built 1998 Load: 32.4 t ADT: 100

BRIDGEGATE DR

Fair

Over: MILLER CREEK

0.1 MI N LUCAS VALLEY RD, Marin, CA

Built 1987 Load: 32.4 t ADT: 500

DOHERTY DR

Fair

Over: ARROYO HOLON

AT ROSE LANE, Marin, CA

Built 2014 Load: 32.4 t ADT: 6,381

ANDERSEN DRIVE

Fair

Over: MAHON CREEK

W OF ANDERSEN & LINDARO, Marin, CA

Built 1997 Load: 32.4 t ADT: 3,500

STATE ROUTE 1

Fair

Over: COYOTE CREEK

04-MRN-001-0.42, Marin, CA

Built 1954 Load: 32.7 t ADT: 30,500

VLY-FRD-FRKLN SCH

Fair

Over: ESTERO AMERICANO

0.85 MI S OF S.R. 1, Marin, CA

Built 1961 Load: 34.0 t ADT: 100

VLY FD FRNKLIN SCH

Fair

Over: ESTERO DE SAN ANTONIO

0.2 MI S WHITAKER BLUF RD, Marin, CA

Built 1964 Load: 35.0 t ADT: 100

PT REYES PETLMA RD

Fair

Over: SAN ANTONIO CREEK

AT MARIN SONOMA CO LINE, Marin, CA

Built 1964 Load: 35.3 t ADT: 1,450

STATE ROUTE 1

Fair

Over: OLEMA CREEK

04-MRN-001-22.81, Marin, CA

Built 1928 Load: 35.6 t ADT: 2,900

SIR-FRANCIS DRAKE

Fair

Over: SAN GERONIMO CREEK

7.6 MI E OF SR 1, Marin, CA

Built 1929 Load: 36.3 t ADT: 3,500

W SAN FRANCISCO BL

Fair

Over: SAN RAFAEL CREEK

JUST S/O SECOND ST, Marin, CA

Built 1981 Load: 39.2 t ADT: 50

MOUNT SHASTA DR

Fair

Over: MILLER CREEK

0.08 MI N LUCAS VALLEY RD, Marin, CA

Built 1962 Load: 39.9 t ADT: 500

SIR FRANCIS DRAKE

Fair

Over: WHITE'S HILL TRAIL

0.6 MI N/O BAYWOOD CYN RD, Marin, CA

Built 2002 Load: 43.4 t ADT: 3,500

LUCAS VALLEY RD

Fair

Over: MILLER CREEK

0.87 MI N OF SR 101, Marin, CA

Built 1959 Load: 49.2 t ADT: 6,500

U.S. HIGHWAY 101

Good

Over: IRWIN CREEK

04-MRN-101-11.20-SRF, Marin, CA

Built 1895 Load: 14.6 t ADT: 129,000

NOKOMIS AVE

Good

Over: SAN ANSELMO CREEK

300 FT N MADRONE AVE, Marin, CA

Built 1930 Load: 15.2 t ADT: 400

ROWLAND WAY

Good

Over: NOVATO CREEK

0.25 MI N ROWLAND BLVD, Marin, CA

Built 1992 Load: 15.9 t ADT: 2,735

PT REYES PETLMA RD

Good

Over: ARROYO SAUSAL(CHSE FACT)

0.5 MI S INTX NWTO BL, Marin, CA

Built 1933 Load: 16.2 t ADT: 2,590

SIR FRANCIS DRAKE

Good

Over: CORTE MADERA CREEK

3.0 MI E OF US HWY 101, Marin, CA

Built 1926 Load: 16.2 t ADT: 32,300

NORWOOD AVE

Good

Over: ROSS CREEK

0.1 MI NORTH OF SHADY LN, Marin, CA

Built 1908 Load: 16.5 t ADT: 1,200

SHADY LANE

Good

Over: ROSS CREEK

NEAR LOCUST ST, Marin, CA

Built 1909 Load: 16.8 t ADT: 1,800

SIR FRANCIS DRAKE

Good

Over: OLEMA CREEK

0.32 MI W SH 1, Marin, CA

Built 1930 Load: 16.8 t ADT: 3,000

REDWOOD BLVD

Good

Over: NOVATO CREEK

0.6 M N ROWLAND BL, Marin, CA

Built 1947 Load: 18.1 t ADT: 9,103

REDWOOD BLVD

Good

Over: NOVATO CREEK

0.6 M N ROWLAND BL, Marin, CA

Built 1929 Load: 20.1 t ADT: 9,103

FALLON-TWO ROCK RD

Good

Over: ESTERO DE SAN ANTONIO

0.02 MI E SR 1, Marin, CA

Built 1932 Load: 20.1 t ADT: 249

COLLEGE AVE

Good

Over: CORTE MADERA CREEK

0.2 MI SO SIR FRNCS DRAKE, Marin, CA

Built 1970 Load: 20.4 t ADT: 6,000

MRSHAL PETALUMA RD

Good

Over: SAN ANTONIO CREEK

0.27 MI E CHILENO VLY RD, Marin, CA

Built 1929 Load: 20.7 t ADT: 328

GRANT AVE

Good

Over: NOVATO CREEK

AT VIRGINIA AVENUE, Marin, CA

Built 1936 Load: 21.1 t ADT: 6,711

DIABLO BLVD

Good

Over: WARNER CREEK

0.1 MI SW OF NOVATO BLVD, Marin, CA

Built 1970 Load: 21.4 t ADT: 7,723

MARSHALL-PETALUMA

Good

Over: SALMON CREEK

0.3M W OF HICKSVALLEY RD, Marin, CA

Built 1928 Load: 21.4 t ADT: 328

SEVENTH ST

Good

Over: NOVATO CREEK

N OF NOVATO BLVD, Marin, CA

Built 1971 Load: 21.7 t ADT: 7,729

CAMINO ALTO

Good

Over: AYO CORTE MADERA DEL PRE

0.15 MI N MILLER AVE, Marin, CA

Built 1970 Load: 22.4 t ADT: 4,000

STATE ROUTE 1

Good

Over: HILLSIDE

04-MRN-001-11.63, Marin, CA

Built 1982 Load: 22.7 t ADT: 3,900

TWIN BRIDGE RD

Good

Over: STEMPLE CREEK

0.22 MI N TMLES-PETLUM RD, Marin, CA

Built 1958 Load: 24.0 t ADT: 80

NICASIO VLY RD

Good

Over: NICASIO DRAIN #1

12.4 MI N OF HWY 101, Marin, CA

Built 1968 Load: 24.3 t ADT: 1,750

LUCKY DRIVE

Good

Over: BRANCH CORTE MADERA CRK

IN CORTE MADERA, Marin, CA

Built 1970 Load: 24.3 t ADT: 3,000

LINDARO ST

Good

Over: MAHON CREEK

SOUTH OF ANDERSEN DR, Marin, CA

Built 1962 Load: 24.3 t ADT: 5,735

REDWOOD HWY

Good

Over: GALLINAS CREEK

IN SAN RAFAEL, Marin, CA

Built 1969 Load: 24.3 t ADT: 16,000

FREITAS PRKY

Good

Over: GALLINAS CREEK

0.3 MI W US HWY 101, Marin, CA

Built 1950 Load: 24.3 t ADT: 8,738

LAS GALINAS AV

Good

Over: GALLINAS CREEK

AT FREITAS PKWY, Marin, CA

Built 1965 Load: 24.3 t ADT: 6,871

Read our methodology - how this data is sourced, computed, and verified.

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Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges

Every figure on PlainBridge is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.