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:

MAPLE HILLS RD

Over: SOUTH FORK EEL RIVER

JUST N/E OF HWY 101, Humboldt, CA

Built 1957 Load: 35.6 t ADT: 1,005

U.S. HIGHWAY 101

Over: BOYD DRAW

01-HUM-101-89.44, Humboldt, CA

Built 1959 Load: 36.0 t ADT: 12,900

SMITH POINT

Over: SOUTH FORK EEL RIVER

OLD SMITH POINT, Humboldt, CA

Built 1934 Load: 36.0 t ADT: 69

BAIR ROAD

Over: SUPPLY CREEK

2 MI W OF LOOP RD, Humboldt, CA

Built 1950 Load: 36.3 t ADT: 69

STEELHEAD RD

Over: POWERS CREEK

2.5 MI E/O ALDERPOINT RD, Humboldt, CA

Built 2007 Load: 37.3 t ADT: 50

WILLIAMS CREEK RD

Over: WILLIAMS CREEK

1.6 MI S GRIZZLY BLUFF RD, Humboldt, CA

Built 1950 Load: 37.6 t ADT: 30

BRICELAND-THORNE

Over: CHINA CREEK

5.2 MI NE SHELTER COVE, Humboldt, CA

Built 1959 Load: 37.9 t ADT: 1,328

U.S. HIGHWAY 101

Over: PATRICKS POINT DR

01-HUM-101-R106.07, Humboldt, CA

Built 1970 Load: 38.9 t ADT: 4,200

ISHI PISHI RD

Over: RANGER FLAT DRAW

0.3 MI N JCT SR 96, Humboldt, CA

Built 1950 Load: 39.2 t ADT: 122

STATE ROUTE 211

Over: OLD RIVER

01-HUM-211-R76.30, Humboldt, CA

Built 1964 Load: 39.5 t ADT: 5,300

U.S. HIGHWAY 101

Over: E BRANCH S FRK EEL RIV

01-HUM-101-R8.80, Humboldt, CA

Built 1968 Load: 40.8 t ADT: 5,700

STATE ROUTE 36

Over: VAN DUZEN RIVER

01-HUM-036-20.21, Humboldt, CA

Built 1965 Load: 41.5 t ADT: 1,200

STATE ROUTE 299

Over: MAINT RD

01-HUM-299-R5.29, Humboldt, CA

Built 1965 Load: 41.5 t ADT: 9,700

WILDER RIDGE ROAD

Over: BEARTRAP CREEK

1.5 MI S MATTOLE RD, Humboldt, CA

Built 1960 Load: 41.8 t ADT: 128

U.S. HIGHWAY 101

Over: STRONGS CREEK

01-HUM-101-59.94, Humboldt, CA

Built 1962 Load: 42.1 t ADT: 13,000

S QUARRY ROAD

Over: JACOBY CREEK

0.05 MI S JACOBY CREEK RD, Humboldt, CA

Built 1971 Load: 42.1 t ADT: 115

U.S. HIGHWAY 101

Over: DEAN CRK RD & DEAN CREEK

01-HUM-101-R14.31, Humboldt, CA

Built 1967 Load: 42.4 t ADT: 5,000

SHIVELEY ROAD

Over: SHIVELEY CREEK

1.0 MI N OF SHIVELEY, Humboldt, CA

Built 1960 Load: 42.4 t ADT: 58

FORT SEWARD ROAD

Over: DOBBYN CREEK

1.5 MI W ALDER POINT RD, Humboldt, CA

Built 1960 Load: 43.4 t ADT: 38

CENTERVILLE ROAD

Over: FLEENER CREEK

2.3 MI WEST OF POOLE RD, Humboldt, CA

Built 1952 Load: 43.7 t ADT: 444

STATE ROUTE 211

Over: SALT RIVER OVERFLOW

01-HUM-211-R74.64, Humboldt, CA

Built 1964 Load: 44.1 t ADT: 5,700

UPPER BEAR RIV RD

Over: BEAR RIVER

8.0 MI S OF MATTOLE RD, Humboldt, CA

Built 1968 Load: 44.7 t ADT: 75

REDWOOD DR

Over: BEAR GULCH

0.2 MI N SR 101 AT GRBRVL, Humboldt, CA

Built 2004 Load: 44.7 t ADT: 5,870

MATTOLE ROAD

Over: WOODS CREEK

1.9 MI SW WILDER RDG RD, Humboldt, CA

Built 1976 Load: 45.4 t ADT: 171

MATTOLE ROAD

Over: SINGLEY CREEK

26.3 MI NORTH OF HONEYDEW, Humboldt, CA

Built 1959 Load: 45.7 t ADT: 308

U. BEAR RIVER ROAD

Over: ARROYO CREEK

6.5 MI S OF MATTOLE RD, Humboldt, CA

Built 1960 Load: 45.7 t ADT: 27

US HIGHWAY 101 SB

Over: SCENIC WAY

01-HUM-101-R53.38-RDEL, Humboldt, CA

Built 1976 Load: 46.3 t ADT: 4,400

US HIGHWAY 101 NB

Over: SCENIC WAY

01-HUM-101-R53.38-RDEL, Humboldt, CA

Built 1976 Load: 48.0 t ADT: 13,000

SPROWEL CREEK ROAD

Over: SPROWEL CREEK

3 MI SW/O KIMTU RD, Humboldt, CA

Built 1959 Load: 48.0 t ADT: 163

MATTOLE ROAD

Over: MATTOLE RIVER

SHIELD'S FORD, Humboldt, CA

Built 1973 Load: 49.6 t ADT: 196

THOMAS ROAD

Over: SALMON CREEK

3.24 MI S SALMON CK RD, Humboldt, CA

Built 1962 Load: 51.5 t ADT: 395

SALMON CREEK ROAD

Over: SALMON CREEK

2 MI W/OF HWY 101, Humboldt, CA

Built 1959 Load: 51.8 t ADT: 300

BLUE SLIDE ROAD

Over: PRICE CREEK

3.9 MI NW OF U.S.101, Humboldt, CA

Built 1959 Load: 53.1 t ADT: 302

ALDERPOINT RD

Over: LARABEE CREEK

32.2 MI E/N FROM SH 101, Humboldt, CA

Built 1960 Load: 53.8 t ADT: 107

US HIGHWAY 101

Over: STAFFORD ROAD

01-HUM-101-R47.95, Humboldt, CA

Built 1971 Load: 55.7 t ADT: 7,500

U.S. HIGHWAY 101

Over: BENBOW DR (OLD US 101)

01-HUM-101-R7.77, Humboldt, CA

Built 1975 Load: 56.1 t ADT: 5,700

MATTOLE ROAD

Over: BEAR RIVER

SOUTH OF PRESCOTT ROAD, Humboldt, CA

Built 1974 Load: 57.0 t ADT: 231

BURREL ROAD

Over: UPPER N FK MATTOLE RIV

0.5 MI W MATTOLE RD, Humboldt, CA

Built 1961 Load: 59.3 t ADT: 142

U.S. HIGHWAY 101

Over: BENBOW DR & S FK EEL RIV

01-HUM-101-R5.63, Humboldt, CA

Built 1980 Load: 68.7 t ADT: 4,500

STATE ROUTE 96

Over: HILLSIDE

01-HUM-096-16.84, Humboldt, CA

Built 1964 Load: 69.3 t ADT: 1,505

HOWE CREEK ROAD

Over: ATWELL CREEK

1.3 MI S/O BLUE SLIDE RD, Humboldt, CA

Built 1960 Load: 70.6 t ADT: 68

UPPER BEAR RIV RD

Over: BEAR RIVER

6.4 MI S OF MATTOLE ROAD, Humboldt, CA

Built 1960 Load: 78.7 t ADT: 27

NO DATA ENTERED

Over: RED CAP CREEK

S19 T10N R6E, Humboldt, CA

Built 1977 ADT: 50

NO DATA ENTERED

Over: N FORK RED CAP CREEK

NO DATA ENTERED, Humboldt, CA

Built 1967 ADT: 50

NO DATA ENTERED

Over: GROUSE CREEK

NO DATA ENTERED, Humboldt, CA

Built 1997 ADT: 50

NO DATA ENTERED

Over: NO DATA ENTERED

S15 T6N R4E, Humboldt, CA

Built 1974 ADT: 50

NO DATA ENTERED

Over: NO DATA ENTERED

NO DATA ENTERED, Humboldt, CA

Built 1988 ADT: 50

NO DATA ENTERED

Over: NO DATA ENTERED

S19 T2N R6E, Humboldt, CA

Built 1983 ADT: 50

TOMPKINS HILL ROAD

Over: SALMON CREEK

0.8 MI SOUTH OF ROUTE 345, Humboldt, CA

Built 1929 Load: 15.2 t ADT: 179

MORGAN SLOUGH ROAD

Over: MORGAN SLOUGH

NORTH OF CAMP WEOTT ROAD, Humboldt, CA

Built 1984 Load: 15.9 t ADT: 31

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

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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 6, 2026