Humboldt County, CA

398 public highway bridges

Humboldt County Bridge Snapshot

Humboldt County, California contains 398 public highway bridges in the FHWA National Bridge Inventory. Roughly 32.9% are rated “Good,” 48.7% “Fair,” 6.3% “Poor,” and 6.3% are classified as structurally deficient — the federal designation for spans whose deck, superstructure, or substructure has been rated 4 or below on the 0–9 NBI scale. Structurally deficient does not mean unsafe to cross; it means the bridge is on the priority list for repair or replacement.

Inspections in CA are conducted by certified engineers from the state Department of Transportation on a 24-month cycle, and results are reported back to the FHWA each spring. The list below shows every NBI-tracked bridge in the county, sorted by inventory load rating. Use the “Sort by” controls to surface the lowest-rated spans first, and click any row for full inspection history, traffic counts, and condition trends.

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

398

Total Bridges

32.9%

Good

6.3%

Poor

6.3%

Structurally Deficient

Condition Distribution

Good

32.9% (131)

Fair

48.7% (194)

Poor

6.3% (25)

SD

6.3% (25)

All Bridges (398)

Sort:

STATE ROUTE 255

Over: MIDDLE CHANNEL

01-HUM-255-0.67-EUR, Humboldt, CA

Built 1971 Load: 22.7 t ADT: 7,300

PINE CREEK RD

Over: SOCTISH CREEK

2.9 MI N OF BAIR RD, Humboldt, CA

Built 1950 Load: 22.7 t ADT: 437

ALDERPOINT RD

Over: EEL RIVER & NWP RR

0.5 MI SE OF ALDERPOINT, Humboldt, CA

Built 1972 Load: 23.0 t ADT: 240

STATE ROUTE 299

Over: RAMP ROAD

01-HUM-299-R4.04, Humboldt, CA

Built 1965 Load: 23.7 t ADT: 9,700

EAST FRONTAGE ROAD

Over: PEDESTRIAN WALKWAY

0.2 MI N 14TH ST, Humboldt, CA

Built 1976 Load: 23.7 t ADT: 2,000

STATE ROUTE 299

Over: ESSEX LANE

01-HUM-299-R2.92, Humboldt, CA

Built 1965 Load: 24.0 t ADT: 11,200

PRICE CREEK ROAD

Over: PRICE CREEK

2.0 MI W BLUE SLIDE ROAD, Humboldt, CA

Built 1953 Load: 24.0 t ADT: 39

BALD HILLS ROAD

Over: KLAMATH RIVER

AT INTERSECTION SR 169, Humboldt, CA

Built 1959 Load: 24.3 t ADT: 43

MCCANN ROAD

Over: EEL RIVER

E DYERVILLE LOOP RD, Humboldt, CA

Built 1965 Load: 24.3 t ADT: 100

STATE PARK ROAD

Over: UPPER DURPHY CREEK

RICHARDSON GROVE ST. PK., Humboldt, CA

Built 1965 Load: 24.3 t ADT: 300

IRR BIA RTE 3

Over: TULLY CREEK

3KM NW MARTIN FERRY BRIDG, Humboldt, CA

Built 1972 Load: 24.5 t ADT: 10

IRR BIA RTE 11

Over: PINE CREEK

16 KM NW OF HOOPA, Humboldt, CA

Built 1977 Load: 24.5 t ADT: 10

IRR BIA RTE 18

Over: PINE CREEK

1.5KM S MARTIN FERRY BD., Humboldt, CA

Built 1977 Load: 24.5 t ADT: 40

US HIGHWAY 101 SB

Over: KING SALMON AVE

01-HUM-101-72.88, Humboldt, CA

Built 1963 Load: 24.9 t ADT: 16,200

US HIGHWAY 101 NB

Over: KING SALMON AVE

01-HUM-101-72.88, Humboldt, CA

Built 1963 Load: 24.9 t ADT: 16,200

STATE ROUTE 211

Over: OLD RIVER

01-HUM-211-R76.46, Humboldt, CA

Built 1964 Load: 24.9 t ADT: 5,300

FORT SEWARD RD

Over: EEL RIVER

6 MI E DYERVILLE LOOP RD, Humboldt, CA

Built 1958 Load: 25.3 t ADT: 350

STATE ROUTE 299

Over: LINDSAY CR,FIELDBROOK RD

01-HUM-299-R3.50, Humboldt, CA

Built 1965 Load: 25.6 t ADT: 11,200

STATE ROUTE 169

Over: RUBE CREEK

01-HUM-169-27.57, Humboldt, CA

Built 1970 Load: 25.6 t ADT: 320

US HIGHWAY 101 SB

Over: PALMER BLVD

01-HUM-101-62.23, Humboldt, CA

Built 1958 Load: 25.9 t ADT: 22,000

US HIGHWAY 101 SB

Over: JORDAN CREEK

01-HUM-101-R46.19, Humboldt, CA

Built 1971 Load: 26.2 t ADT: 3,600

KNEELAND ROAD

Over: LAWRENCE CREEK

26.1 MI NE/O BRIDGEVILLE, Humboldt, CA

Built 1949 Load: 26.2 t ADT: 28

US HIGHWAY 101 NB

Over: PALMER BLVD

01-HUM-101-62.23, Humboldt, CA

Built 1958 Load: 26.6 t ADT: 22,000

RIVERWALK DRIVE

Over: STRONGS CREEK

0.9 MI NORTH OF HWY 101, Humboldt, CA

Built 1962 Load: 26.9 t ADT: 2,322

FAIRWAY DR

Over: MARTIN SLOUGH

1 MI EAST OF SR 101, Humboldt, CA

Built 1964 Load: 26.9 t ADT: 9,240

STATE ROUTE 36

Over: BUTTE CREEK

01-HUM-036-34.52, Humboldt, CA

Built 1960 Load: 27.5 t ADT: 1,200

ACCESS ROAD TO CDF

Over: BROWNS CREEK

NE OFKNEELAND,BRIDGEVILLE, Humboldt, CA

Built 2012 Load: 27.5 t ADT: 12

U.S. HIGHWAY 101

Over: EEL RIVER & NCRRA

01-HUM-101-R48.69, Humboldt, CA

Built 1965 Load: 27.9 t ADT: 5,900

US HIGHWAY 101 NB

Over: ELK RIVER

01-HUM-101-74.60, Humboldt, CA

Built 1988 Load: 27.9 t ADT: 16,200

BLUE SLIDE RD

Over: HOWE CREEK

JCT HOWE CREEK ROAD, Humboldt, CA

Built 1978 Load: 27.9 t ADT: 346

STATE ROUTE 254

Over: GREENLAW CREEK

01-HUM-254-46.12, Humboldt, CA

Built 1959 Load: 28.2 t ADT: 330

STATE ROUTE 299

Over: GLENDALE DR

01-HUM-299-R3.78, Humboldt, CA

Built 1965 Load: 28.2 t ADT: 11,200

ALDERPOINT ROAD

Over: NORTH DOBBYN CREEK

5 MI N/O ALDERPOINT, Humboldt, CA

Built 1966 Load: 28.2 t ADT: 201

ALDERPOINT RD

Over: LARABEE CREEK

15.5 MI N ALDER POINT, Humboldt, CA

Built 1966 Load: 28.5 t ADT: 124

RIVER BAR ROAD

Over: BARBER CREEK WASH

0.6 MI SOUTH OF RTE 36, Humboldt, CA

Built 1970 Load: 28.5 t ADT: 351

STATE ROUTE 36

Over: SOUTH FORK VAN DUZEN RIV

01-HUM-036-35.37, Humboldt, CA

Built 1962 Load: 28.8 t ADT: 1,200

U.S. HIGHWAY 101

Over: WESTHAVEN DRIVE

01-HUM-101-98.07, Humboldt, CA

Built 1960 Load: 29.2 t ADT: 8,800

US HIGHWAY 101 NB

Over: N CENTRAL AVE

01-HUM-101-R95.62, Humboldt, CA

Built 1964 Load: 29.2 t ADT: 16,500

FRESHWATER POOL RD

Over: FRESHWATER CREEK

0.03 MI S FRESHWATER RD, Humboldt, CA

Built 1972 Load: 29.2 t ADT: 100

MAPLE CREEK ROAD

Over: HEATH CREEK

3.12 MI S BUTLER VLY RD, Humboldt, CA

Built 1961 Load: 29.5 t ADT: 17

ISHI PISHI ROAD

Over: WILSON CREEK

3.1 MI S JCT WITH SR 96, Humboldt, CA

Built 1975 Load: 29.5 t ADT: 132

U.S. HIGHWAY 101

Over: GIBNEY DRIVE

01-HUM-101-R22.44, Humboldt, CA

Built 1964 Load: 30.1 t ADT: 5,100

U.S. HIGHWAY 101

Over: BEAR CREEK

01-HUM-101-R42.99, Humboldt, CA

Built 1967 Load: 30.5 t ADT: 6,000

CAPPELL RD

Over: MAREEP CREEK

5.27 MI S JCT RTE 169, Humboldt, CA

Built 1965 Load: 30.5 t ADT: 150

STATE ROUTE 96

Over: HILLSIDE

01-HUM-096-16.82, Humboldt, CA

Built 1964 Load: 30.8 t ADT: 1,505

STATE ROUTE 254

Over: SOUTH FORK EEL RIVER

01-HUM-254-20.64, Humboldt, CA

Built 1931 Load: 31.1 t ADT: 460

U.S. HIGHWAY 101

Over: SOUTH FORK EEL RIVER

01-HUM-101-27.71, Humboldt, CA

Built 1962 Load: 31.1 t ADT: 5,000

PRICE CREEK ROAD

Over: SWEET CREEK

3.4 MI W BLUE SLIDE RD, Humboldt, CA

Built 1959 Load: 31.1 t ADT: 39

MAPLE CREEK RD

Over: CANYON CREEK

7.25 MI S INTX SR 299, Humboldt, CA

Built 1951 Load: 31.4 t ADT: 55

STATE ROUTE 299

Over: REDWOOD CREEK

01-HUM-299-R22.33, Humboldt, CA

Built 1965 Load: 31.8 t ADT: 3,200

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

Related

Browse all → | Rankings →

Data sourced from official U.S. government datasets. See our methodology for details. Retrieved and formatted by PlainBridges Editorial

Reviewed byPlainbridges Editorial, Plain Bridges Editorial Team · June 5, 2026