Siskiyou County, CA

423 public highway bridges

Siskiyou County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Siskiyou County, California contains 423 public highway bridges. Roughly 36.2% are rated “Good,” 49.6% “Fair,” and 5.4% “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.

423
Total Bridges
36.2%
Good
49.6%
Fair
5.4%
Poor Condition

Condition Distribution

Good
36.2% (153)
Fair
49.6% (210)
Poor
5.4% (23)

All Bridges (423)

INTERSTATE 5

Fair

Over: CRAM GULCH

02-SIS-005-R39.02, Siskiyou, CA

Built 1969 Load: 37.6 t ADT: 7,850

INTERSTATE 5 NB

Fair

Over: SISKIYOU WAY

02-SIS-005-R18.71-WEED, Siskiyou, CA

Built 1973 Load: 37.6 t ADT: 7,150

COTTONWOOD CR RD

Fair

Over: DITCH CREEK

0.25 MI N/O DITCH CRK RD, Siskiyou, CA

Built 1968 Load: 38.2 t ADT: 95

MOFFETT CREEK RD

Fair

Over: MOFFETT CREEK

4.4 MI E SR 3, Siskiyou, CA

Built 1975 Load: 38.6 t ADT: 145

AGER RD

Fair

Over: BLACK MOUNTAIN GULCH

7.6 MI NORTH SR 3, Siskiyou, CA

Built 1980 Load: 38.9 t ADT: 648

INTERSTATE 5 NB

Fair

Over: UP RR & AMTRAK

02-SIS-005-R15.94, Siskiyou, CA

Built 1973 Load: 39.2 t ADT: 12,750

INTERSTATE 5

Fair

Over: GUYS GULCH

02-SIS-005-R39.27, Siskiyou, CA

Built 1969 Load: 39.9 t ADT: 8,300

SOUTH FORK ROAD

Fair

Over: SOUTH FORK SCOTT RIVER

E/O CECILVILLE ROAD, Siskiyou, CA

Built 1969 Load: 40.2 t ADT: 49

QUARTZ VALLEY ROAD

Fair

Over: SHACKLEFORD CREEK

3.6 MI S SCOTT RIVER RD, Siskiyou, CA

Built 1967 Load: 40.5 t ADT: 330

STATE ROUTE 3

Fair

Over: EAST FORK SCOTT RIVER

02-SIS-003-6.90, Siskiyou, CA

Built 1968 Load: 41.1 t ADT: 190

STATE ROUTE 96

Fair

Over: KLAMATH RIVER

02-SIS-096-R15.61, Siskiyou, CA

Built 1967 Load: 41.5 t ADT: 330

HAWKINSVLE HUMB RD

Fair

Over: HUMBUG CREEK

SOUTH HUMBUG CREEK RD, Siskiyou, CA

Built 1971 Load: 41.5 t ADT: 20

BEAVER CREEK ROAD

Fair

Over: BEAVER CREEK

BEAVER, Siskiyou, CA

Built 1963 Load: 42.8 t ADT: 50

INTERSTATE 5 NB

Fair

Over: UP RR & AMTRAK

02-SIS-005-R9.20, Siskiyou, CA

Built 1964 Load: 43.7 t ADT: 20,000

STATE ROUTE 3

Fair

Over: WILDCAT CREEK

02-SIS-003-9.75, Siskiyou, CA

Built 1958 Load: 43.7 t ADT: 925

SERPA LANE

Fair

Over: KIDDER CREEK

0.45 MI E OF SR 3, Siskiyou, CA

Built 1967 Load: 44.4 t ADT: 164

STATE ROUTE 3

Fair

Over: MILL CREEK

02-SIS-003-6.82, Siskiyou, CA

Built 1970 Load: 45.4 t ADT: 190

STATE ROUTE 3

Fair

Over: SOUTH FORK SCOTT RIVER

02-SIS-003-8.89, Siskiyou, CA

Built 1958 Load: 46.0 t ADT: 345

GAZELLE-CALLAHAN R

Fair

Over: NOYES VALLEY CREEK

0.1 MI N MASTERSON RD, Siskiyou, CA

Built 1972 Load: 46.0 t ADT: 287

FRENCH CREEK RD

Fair

Over: FRENCH CREEK

5.2 MI S OF S.H. 3, Siskiyou, CA

Built 1990 Load: 46.3 t ADT: 20

CECILVILLE ROAD

Fair

Over: MCNEAL CREEK

1 MI S/O SALMON RIVER RD, Siskiyou, CA

Built 1937 Load: 46.7 t ADT: 101

INTERSTATE 5 SB

Fair

Over: SISKIYOU WAY

02-SIS-005-R18.71-WEED, Siskiyou, CA

Built 1973 Load: 47.3 t ADT: 7,150

CARIBOU ROAD

Fair

Over: RAYS GULCH

4.7 MI S/O CECILVILLE RD, Siskiyou, CA

Built 1982 Load: 47.3 t ADT: 29

INTERSTATE 5 NB

Fair

Over: HUTTON CREEK

02-SIS-005-R64.82R, Siskiyou, CA

Built 1974 Load: 47.6 t ADT: 15,300

INTERSTATE 5 NB

Fair

Over: COTTONWOOD CREEK

02-SIS-005-R63.65R, Siskiyou, CA

Built 1974 Load: 48.3 t ADT: 15,300

DOOLITTLE CREEK RD

Fair

Over: INDIAN CREEK

AT INDIAN CREEK RD, Siskiyou, CA

Built 1965 Load: 48.6 t ADT: 79

MCADAMS CREEK RD

Fair

Over: MOFFETT CREEK

0.25 MI N SR 3, Siskiyou, CA

Built 1978 Load: 52.8 t ADT: 256

CECILVILLE ROAD

Fair

Over: NORTH FORK SALMON RIVER

S/O SALMON RIVER ROAD, Siskiyou, CA

Built 1985 Load: 54.4 t ADT: 116

EAST-WEST RD

Fair

Over: LOST RIVER

1.8 MI W SR 139, Siskiyou, CA

Built 1984 Load: 54.4 t ADT: 827

GRIDER ROAD

Fair

Over: GRIDER CREEK

2.7 MI S SR 96, Siskiyou, CA

Built 1976 Load: 54.4 t ADT: 94

FRENCH CR RD

Fair

Over: FRENCH CREEK

3.7 MI S SR 3, Siskiyou, CA

Built 1986 Load: 54.4 t ADT: 245

INTERSTATE 5 SB

Fair

Over: COTTONWOOD CREEK

02-SIS-005-R63.77L, Siskiyou, CA

Built 1974 Load: 55.1 t ADT: 7,300

CURLY JACK ROAD

Fair

Over: ELK CREEK

0.8 MI S OF ELK CREEK RD, Siskiyou, CA

Built 1975 Load: 55.4 t ADT: 624

ANDERSON GRADE RD

Fair

Over: YREKA CREEK

0.1 MI E OF SR 263, Siskiyou, CA

Built 1971 Load: 56.7 t ADT: 90

ISLAND ROAD

Fair

Over: SCOTT RIVER OVERFLOW

0.5 MI E HOLZHAUSER LANE, Siskiyou, CA

Built 1977 Load: 57.0 t ADT: 158

ISLAND ROAD

Fair

Over: SCOTT RIVER OVERFLOW

0.2 MI W OF EASTSIDE RD, Siskiyou, CA

Built 1977 Load: 57.3 t ADT: 161

ISLAND ROAD

Fair

Over: SCOTT RIVER OVERFLOW

0.1 MI W OF ISLAND RD, Siskiyou, CA

Built 1977 Load: 58.3 t ADT: 86

EDGEWOOD ROAD

Fair

Over: SHASTA RIVER

0.1 MI W OL EDGEWOOD WEED, Siskiyou, CA

Built 1973 Load: 59.9 t ADT: 395

CARIBOU ROAD

Fair

Over: SOUTH FORK SALMON RIVER

4 MI S/O CECILVILLE ROAD, Siskiyou, CA

Built 1984 Load: 64.8 t ADT: 48

TENNANT RD

Fair

Over: ANTELOPE CREEK

11.6 MI SE SR97, Siskiyou, CA

Built 1971 Load: 66.4 t ADT: 79

SAWYERS BAR RD

Fair

Over: NORTH FORK SALMON RIVER

3 MI N WHITES GULCH RD, Siskiyou, CA

Built 1982 Load: 68.0 t ADT: 105

MCADAMS CREEK RD

Fair

Over: MCADAMS CREEK

2.55 MI N SR 3, Siskiyou, CA

Built 1975 Load: 73.9 t ADT: 256

SLOUGH RD

Fair

Over: LOWER PARKS CREEK

4.1 MI S OF LOUIE RD, Siskiyou, CA

Built 1975 Load: 76.8 t ADT: 7

CECILVILLE ROAD

Fair

Over: SOUTH FORK SALMON RIVER

0.1 MI S/O SALMON RIVER R, Siskiyou, CA

Built 1986 Load: 78.1 t ADT: 116

FISH LAKE ROAD

Fair

Over: E. FORK SALMON RIVER

CALLAHAN, Siskiyou, CA

Built 1966 Load: 90.8 t ADT: 15

WRIGHTS LAKE ROAD

Fair

Over: BOULDER CREEK

SCOTT BAR, Siskiyou, CA

Built 1967 Load: 90.8 t ADT: 50

INTERSTATE 5

Fair

Over: LITTLE CASTLE CREEK

02-SIS-005-0.04, Siskiyou, CA

Built 1960 Load: 99.9 t ADT: 18,000

YREKA HEADQUARTERS

Good

Over: YREKA CREEK

GUNSIGHT, Siskiyou, CA

Built 1975 ADT: 50

MCKINNEY CREEK RD

Good

Over: MCKINNEY CREEK

GUNSIGHT, Siskiyou, CA

Built 1976 ADT: 50

WEST BEAVER ROAD

Good

Over: JAYNES CANYON

BEAVER, Siskiyou, CA

Built 1976 ADT: 50

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.