How Sepulveda Canyon Became the 405
For centuries the region’s native Tongva people had hiked a faint footpath through Sepulveda Canyon, and in 1769 the soldiers and clergy of Spain’s Portola expedition followed that ancient trade route on their way to Monterey. Trail became road in 1875, when the two wheat barons of the San Fernando Valley, Isaac Lankershim and Isaac Newton Van Nuys, widened the footpath to allow for the passage of sturdy wagons laden with grain and bound for ships docked at the Santa Monica Pier. But when the Southern Pacific soon lowered its freight rates, the wheat ranchers instead sent their harvest by train to San Pedro. The new, neglected road eroded into the hillsides.
Eventually, booming development in the San Fernando Valley during the 1920s persuaded the city and county to rebuild the road for automobiles. Traffic was overwhelming the two established routes between the Valley and the Basin, Cahuenga Pass and San Fernando Road, both of which were out of the way for residents of faraway Van Nuys and Owensmouth. New Sepulveda Boulevard – a 50-mile highway stretching between San Fernando and Long Beach – would provide the Valley with a more direct link to the Basin and harbor beyond at San Pedro Bay.