Humboldt County, CA

398 public highway bridges

Humboldt County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Humboldt County, California contains 398 public highway bridges. Roughly 32.9% are rated “Good,” 48.7% “Fair,” and 6.3% “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.

398
Total Bridges
32.9%
Good
48.7%
Fair
6.3%
Poor Condition

Condition Distribution

Good
32.9% (131)
Fair
48.7% (194)
Poor
6.3% (25)

All Bridges (398)

U.S. HIGHWAY 101

Good

Over: LOST MAN CREEK

01-HUM-101-124.71, Humboldt, CA

Built 1986 Load: 32.4 t ADT: 3,700

STATE ROUTE 299

Good

Over: SOUTH FORK TRINITY RIVER

01-HUM-299-42.95, Humboldt, CA

Built 1988 Load: 32.4 t ADT: 4,400

STATE ROUTE 36

Good

Over: GRIZZLY CREEK

01-HUM-036-16.94, Humboldt, CA

Built 1996 Load: 32.4 t ADT: 1,650

U.S. HIGHWAY 101

Good

Over: NEWTON ROAD

01-HUM-101-33.22, Humboldt, CA

Built 1961 Load: 32.4 t ADT: 6,190

STATE ROUTE 36

Good

Over: VAN DUZEN RIVER

01-HUM-036-40.45, Humboldt, CA

Built 1981 Load: 32.4 t ADT: 1,000

STATE ROUTE 96

Good

Over: SUPPLY CREEK

01-HUM-096-11.62, Humboldt, CA

Built 1991 Load: 32.4 t ADT: 2,850

STATE ROUTE 96

Good

Over: MILL CREEK

01-HUM-096-R14.55, Humboldt, CA

Built 1993 Load: 32.4 t ADT: 1,505

U.S. HIGHWAY 101

Good

Over: SOUTH FORK EEL RIVER

01-HUM-101-R7.87, Humboldt, CA

Built 1969 Load: 32.4 t ADT: 5,700

STATE ROUTE 299

Good

Over: WILLOW CREEK

01-HUM-299-35.55, Humboldt, CA

Built 1956 Load: 32.4 t ADT: 3,200

U.S. HIGHWAY 101

Good

Over: HOOKER CREEK ROAD

01-HUM-101-R16.51, Humboldt, CA

Built 1965 Load: 32.4 t ADT: 6,700

STATE ROUTE 299

Good

Over: HILLSIDE

01-HUM-299-R42.30, Humboldt, CA

Built 1966 Load: 32.4 t ADT: 4,400

STATE ROUTE 169

Good

Over: ROCK CHUTE CREEK

01-HUM-169-29.83, Humboldt, CA

Built 1991 Load: 32.4 t ADT: 320

US HIGHWAY 101 NB

Good

Over: EEL RIV,EDWARDS DR,NCRRA

01-HUM-101-R51.99, Humboldt, CA

Built 1976 Load: 32.4 t ADT: 5,500

STATE ROUTE 255

Good

Over: MAD RIVER SLOUGH

01-HUM-255-R5.13, Humboldt, CA

Built 1981 Load: 32.4 t ADT: 4,300

STATE ROUTE 36

Good

Over: VAN DUZEN RIVER

01-HUM-036-17.94, Humboldt, CA

Built 1985 Load: 32.4 t ADT: 1,650

SANDY PRAIRIE ROAD

Good

Over: VAN DUZEN RIVER OVERFLOW

01-HUM-000-0.00, Humboldt, CA

Built 2009 Load: 32.4 t ADT: 30

STATE ROUTE 254

Good

Over: HILLSIDE

01-HUM-254-11.83, Humboldt, CA

Built 1989 Load: 32.4 t ADT: 565

STATE ROUTE 36

Good

Over: VAN DUZEN RIVER

01-HUM-036-R23.91, Humboldt, CA

Built 1997 Load: 32.4 t ADT: 1,200

STATE ROUTE 96

Good

Over: HOSTLER CREEK

01-HUM-096-R13.26, Humboldt, CA

Built 1992 Load: 32.4 t ADT: 1,505

STATE ROUTE 254

Good

Over: HILLSIDE

01-HUM-254-17.80-STPK, Humboldt, CA

Built 1995 Load: 32.4 t ADT: 565

STATE ROUTE 169

Good

Over: MAWAH CREEK

01-HUM-169-24.98, Humboldt, CA

Built 2012 Load: 32.4 t ADT: 2,000

STATE ROUTE 169

Good

Over: RUBE RANCH CREEK

01-HUM-169-28.49, Humboldt, CA

Built 2012 Load: 32.4 t ADT: 2,000

STATE ROUTE 169

Good

Over: MARTINS FERRY SCHOOL CRK

01-HUM-169-29.95, Humboldt, CA

Built 2012 Load: 32.4 t ADT: 345

US HIGHWAY 101 SB

Good

Over: MAD RIVER

01-HUM-101-89.63, Humboldt, CA

Built 2011 Load: 32.4 t ADT: 18,500

U.S. HIGHWAY 101

Good

Over: LITTLE LOST MAN CREEK

01-HUM-101-124.48, Humboldt, CA

Built 2020 Load: 32.4 t ADT: 4,200

US HIGHWAY 101 SB

Good

Over: JACOBY CREEK

01-HUM-101-84.50-ARC, Humboldt, CA

Built 2022 Load: 32.4 t ADT: 18,125

LANPHERE ROAD

Good

Over: MAD RIVER SLOUGH

2.5 MI WEST OF SR 101, Humboldt, CA

Built 1988 Load: 32.4 t ADT: 45

ELK RIVER ROAD

Good

Over: MARTIN SLOUGH

0.2 MI SE OF SR 101, Humboldt, CA

Built 1992 Load: 32.4 t ADT: 4,801

GLENDALE DR

Good

Over: LINDSAY CREEK

JUST NW OF FIELDBROOK RD, Humboldt, CA

Built 1995 Load: 32.4 t ADT: 1,520

GOLDEN GATE DR

Good

Over: VAN DUZEN RIVER

0.5 MI S OF SR 36, Humboldt, CA

Built 1985 Load: 32.4 t ADT: 58

WHITLOW RD

Good

Over: SONOMA CREEK

1 MI N OF SEQUOIA RD, Humboldt, CA

Built 1986 Load: 32.4 t ADT: 53

KINGS PEAK ROAD

Good

Over: NORTH FORK BEAR CREEK

2 MI S/O WILDER RIDGE RD, Humboldt, CA

Built 1993 Load: 32.4 t ADT: 75

BEAR RIVER ROAD

Good

Over: BONANZA GULCH

8.5 MI S OF MATTOLE RD, Humboldt, CA

Built 1986 Load: 32.4 t ADT: 15

MATTOLE ROAD

Good

Over: DAVIS CREEK

7.2 MI NW OF PETROLIA, Humboldt, CA

Built 1998 Load: 32.4 t ADT: 700

OLD ARCATA RD

Good

Over: JACOBY CREEK

1/4 MI N BAYSIDE CUTOFF, Humboldt, CA

Built 1988 Load: 32.4 t ADT: 3,030

MAPLE HILLS ROAD

Good

Over: SALMON CREEK

JUST S/O SALMON CREEK RD, Humboldt, CA

Built 1982 Load: 32.4 t ADT: 349

DEVOY RD

Good

Over: FRESHWATER SLOUGH

AT MYRTLE AVE, Humboldt, CA

Built 1986 Load: 32.4 t ADT: 24

MYRTLE AVE

Good

Over: FRESHWATER CR OVERFLOW

0.4 MI W OF KNEELAND RD, Humboldt, CA

Built 1984 Load: 32.4 t ADT: 6,908

RED CAP ROAD

Good

Over: BOISE CREEK

3.7 MILE S. OF SR 96, Humboldt, CA

Built 1995 Load: 32.4 t ADT: 91

PRICE CREEK ROAD

Good

Over: PRICE CREEK

0.9 MI W BLUE SLIDE ROAD, Humboldt, CA

Built 1996 Load: 32.4 t ADT: 67

LIGHTHOUSE ROAD

Good

Over: MILL CREEK

1.5 MI SW OF MATTOLE RD, Humboldt, CA

Built 2003 Load: 32.4 t ADT: 3

MATTOLE ROAD

Good

Over: INDIAN CREEK

4.5 MI S/O PETROLIA, Humboldt, CA

Built 2010 Load: 32.4 t ADT: 240

RED CAP ROAD

Good

Over: BIG ROCK GULCH

0.3 MILES SW OF SR96, Humboldt, CA

Built 2019 Load: 32.4 t ADT: 425

PORT KENYON ROAD

Good

Over: FRANCIS CREEK

0.5 MI W OF MAIN STREET, Humboldt, CA

Built 2015 Load: 32.4 t ADT: 500

IRR BIA RTE 15

Good

Over: HOSTLER CREEK

3 KM NORTH OF HOOPA, Humboldt, CA

Built 1962 Load: 32.4 t ADT: 200

STATE ROUTE 299

Good

Over: MILL CREEK

01-HUM-299-R4.21, Humboldt, CA

Built 1965 Load: 32.7 t ADT: 9,700

U.S. HIGHWAY 101

Good

Over: SORENSON ROAD

01-HUM-101-R39.67, Humboldt, CA

Built 1967 Load: 32.7 t ADT: 6,190

STATE ROUTE 96

Good

Over: BLUFF CREEK

01-HUM-096-R28.91, Humboldt, CA

Built 1967 Load: 32.7 t ADT: 540

U.S. HIGHWAY 101

Good

Over: OAKCREST COURT

01-HUM-101-R8.60, Humboldt, CA

Built 1969 Load: 33.0 t ADT: 5,700

U.S. HIGHWAY 101

Good

Over: WILLIFORD ROAD

01-HUM-101-30.50, Humboldt, CA

Built 1961 Load: 34.0 t ADT: 5,450

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.