Central Pacific Transcontinental Railroad, Tunnel No. 4, Milepost 180.95, Cisco, Placer County, CA

Significance: The Central Pacific First Transcontinental Railroad is a segment of the western half of the first transcontinental railroad, built from Sacramento, California to Promontory Summit, Utah between 1863 and 1869, where it joined the Union Pacific Railroad which had built west from Omaha. For the purpose of the current project, the first transcontinental railroad was found likely to be eligible for the National Register of Historic Places at the national level of significance under Criterion A for its significance in transportation history, in uniting the East and the West, and in the development of the West. The railroad's period of significance is 1869 to 1945, from the line's completion in 1869, through the years of its role in the settlement and development of the West, to the conclusion of the railroad's achievements in World War II. Tunnel 4 is a contributive element of this historic property.
Survey number: HAER CA-214
Building/structure dates: 1868 Initial Construction
Building/structure dates: 1921 Subsequent Work
Building/structure dates: 1942 Subsequent Work