Historic Bridges in California

4,414 bridges built before 1951 in California still in service today.

Bridges Built Before 1951

The United States has 4,414 bridges in California built before 1951 that remain in active service. These structures are 75+ years old — many predate modern engineering codes and were not designed for today's traffic volumes and vehicle weights. The average design life of a bridge is 50 years, making these aging structures a significant infrastructure concern.

Clear
Bridge State Condition Year Built Age (Years) ADT
PALO VERDE LAGOON California Fair 1950 76 300
PALO VERDE LAGOON California Fair 1950 76 800
MOHAVE LATERAL CANAL California Fair 1950 76 250
RESERVATION MAIN DRAIN California Fair 1950 76 10
CENTRAL MAIN CANAL California Fair 1950 76 570
CENTRAL MAIN CANAL California Fair 1950 76 120
RESERVATION MAIN DRAIN California Good 1950 76 50
FOURMILE CREEK California Good 1950 76 50
FIVEMILE CREEK California Good 1950 76 50
S FORK FEATHER RIVER California Good 1950 76 5
GLEN CREEK California Fair 1950 76 50
NOSONI CREEK California Good 1950 76 30
SOUTH FORK KINGS RIVER California Fair 1950 76 278
MISSION CREEK California Fair 1950 76 1

About Historic Bridge Data

Bridges built before 1951 are classified as historic in this database. Many were designed to 1940s standards with lower load limits and narrower lanes. While FHWA requires regular inspections of all bridges regardless of age, older structures often require more frequent monitoring and rehabilitation investment.