Salinas River Project, Cuesta Tunnel, Southeast of U.S. 101, San Luis Obispo, San Luis Obispo County, CA

Significance: The Cuesta Tunnel is important as an example of the heroic engineering and construction undertaken by the U.S. Army Quartermaster Corps in the early 1940s as part of the mobilization of American forces prior to World War II. The tunnel was constructed in less than 9 months from planning to use, an astonishing rate of construction given the length and diameter of the tunnel. While not unusually large or long in the general context of tunnels in California, the Cuesta Tunnel is an important example of the work of the Quartermaster Corps and private engineering and construction firms under mobilization conditions.
Survey number: HAER CA-153-A
Building/structure dates: 1942 Initial Construction