Interstate 40 within California is entirely contained to San Bernandio County over a course of 155 miles from Interstate 15 in Barstow east to the Arizona State Line at the Colorado River. Interstate 40 is aligned entirely in the Mojave Desert over the same general corridor established by US Route 66 and the National Old Trails Road. Interstate 40 is known as the Needles Freeway and has an interesting backstory which included the prospect of the Bristol Mountains being excavated by way of nuclear blasts as part of Operation Carryall.
Part 1; the history of Interstate 40 in California
The focus on this blog will be primarily centered around the construction of Interstate 40 ("I-40") within California. That being said the corridor of automotive travel east of Barstow to the Arizona State Line was largely pioneered by the National Old Trails Road ("NOTR"). In April of 1912 the NOTR was organized with the goal of signing a trans-continental highway between Baltimore and Los Angeles. Building a modern road for automotive use through the Mojave Desert of California would prove to be particularly difficult as State Highway Maintenance didn't exist and the general path of travel was alongside the service routes of the Atchison, Topeka and Santa Fe Railroad ("ATSF"). The first Auto Trail through the Mojave Desert of California to Cajon Pass was the Santa Fe-Grand Canyon Needles National Highway which was first signed by 1913. NOTR organizers later adopted the routing of the Santa Fe-Grand Canyon Needles National Highway in the western United States by 1914.
The NOTR in the Mojave Desert east of Barstow to the Arizona State Line can be seen in detail on the 1916 NOTR Map.