Editing Valley Springs, California (section)

=== Industrial expansion ===
In 1925, Southern Pacific extended the rail line 13 miles east to Kentucky House to serve the Calaveras Cement Company.<ref name=":1" /> This extension facilitated the development of the Pardee Dam and the shipment of cement to customers such as the Bay Area. Major projects like the McClellan and Travis Air Force bases, San Francisco Airport, Central Valley dams, and the San Francisco-Oakland Bay Bridge were built using cement transported from Valley Springs. The construction of the Hogan Dam and Pardee Dam increased employment. Local industries, including lumber, forest products, cement, and clay, boosted shipping needs. Agriculture remained the primary occupation, focusing on grains, livestock, and small-scale wine grapes and olives. Valley Springs’ strategic location was key to its importance. The 1930s and 1940s saw a 6% annual population increase. Population growth flattened in the 1950s but surged again in the 1960s due to the development of the Camanche Reservoir and the expansion of the Hogan Reservoir.<ref name=":0" />