Union Pacific Railroad Bridge, Spanning Santa Anna River, west of Riverside, Riverside, Riverside County, CA
Significance: The Union Pacific Railroad Bridge was part of an overall plan initiated by Senator William Andrews Clark to connect the rail centers of Salt Lake City and Los Angeles, thereby creating a route of strategic importance for the shipping and transportation of materials. The Bridge was also, at one time, the largest concrete bridge on earth.
Survey number: HAER CA-123
Building/structure dates: 1904 Initial Construction