Siskiyou County Bridge Report Card

Siskiyou County scores 78 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.

C78 / 100

Local infrastructure snapshot

Siskiyou County, California

Siskiyou County has 425 bridges in the National Bridge Inventory, with 25 rated poor and 12 rated scour-critical. Its poor-condition share of 5.9% is above the 4.9% statewide average. Poor-condition bridges carry about 20,945 daily vehicle crossings.

425Total Bridges

25Poor (5.9%)

230Fair (54.1%)

12Scour-Critical

Quote-Ready Local Facts

5.9%of county bridges are in poor condition, compared with 4.9% statewide and 6.7% nationally.

20,945daily vehicle crossings are on poor-condition bridges in the county.

12bridges are rated scour-critical, or 2.8% of the county bridge inventory.

Copyable Facts for Reporters

BridgeLookup.com gives Siskiyou County a Bridge Condition Exposure Score of 78/100 (C). The county has 425 bridges in the National Bridge Inventory, including 25 in poor condition and 12 rated scour-critical. Poor-condition bridges carry about 20,945 daily vehicle crossings. Poor condition does not mean unsafe; bridges judged unsafe are closed or restricted by transportation agencies.

Download all county report-card scores as CSV.

How the Score Breaks Down

Factor	Weight	County Value	Penalty
Poor-condition bridge share	40	5.9%	11.8
Poor-condition traffic exposure	25	2.4% of measured traffic	1.8
Scour-critical bridge share	20	2.8%	5.6
Average age vs national baseline	10	54 years vs 48 nationally	2.6
Traffic-data completeness	5	882,970 measured daily crossings	0.0

Score = 100 minus weighted penalties. The score is a comparative research signal, not an official safety rating. Read the full methodology.

County Comparisons

County Poor-Condition Share	5.9%
State Poor-Condition Share	4.9%
National Poor-Condition Share	6.7%
County Scour-Critical Share	2.8%
Average Bridge Age	54 years
Poor-Condition Traffic Exposure	20,945 vehicles/day

Bridges to Watch

Busiest Poor-Condition BridgeInterstate 5 over Panorama Road — 18,000 vehicles/day Oldest Listed BridgeScott River RD over Middle Creek — built in 1900 All County BridgesBrowse every bridge record in Siskiyou County.

Top Bridges to Watch in Siskiyou County

Bridge	Reason	Condition	Daily Traffic	Year Built
Hospital Road over Yreka Creek	Poor condition + traffic exposure	Poor	200	1987
Eller Lane over Scott River	Poor condition + traffic exposure	Poor	172	1910
China Mt. Road over Houston Creek	Poor condition + traffic exposure	Poor	50	1974
Tom Walker Road over Tompkins Creek	Poor condition + traffic exposure	Poor	50	1988
Wildcat Creek Road over Scott River	Poor condition + traffic exposure	Poor	20	1909
No Data Entered over Boulder Creek	Poor condition + traffic exposure	Poor	2	1967
Interstate 5 over Panorama Road	Poor condition + traffic exposure	Poor	18,000	1960
State Route 96 over Thompson Creek	Poor condition + traffic exposure	Poor	615	1952
State Route 96 over Scott River	Poor condition + traffic exposure	Poor	600	1957
N Old Stage RD over Shasta River	Poor condition + traffic exposure	Poor	379	1968

Important safety note

Poor condition does not mean a bridge is unsafe. It means at least one major component has significant deterioration and the bridge is a priority for maintenance, repair, or replacement. Bridges judged unsafe are closed or restricted by transportation agencies.