Historical Timeline
Pre-1800s: Long before roads or railroads, the Serrano people traveled through Cajon Pass. It was a natural corridor between the Mojave Desert and the valleys to the south — a well-worn trail for trade, gathering, and seasonal movement.
1776: Spanish explorers, including Father Francisco Garcés, came through the pass. It soon became part of what would later be called the Old Spanish Trail, linking New Mexico to California.
1830: Trader Antonio Armijo officially led a commercial caravan through Cajon Pass, making it part of the main route for trade between Santa Fe and Los Angeles.
1848: A few former members of the Mormon Battalion managed to get a wagon through the pass, proving that the steep, rocky route could support overland wagon travel.
1851: A group of Mormon pioneers, led by Amasa Lyman and Charles Rich, brought dozens of wagons through the pass as they headed to start the settlement of San Bernardino.
1861: John Brown Sr. built a toll road through Cajon Pass. It made travel easier for wagons and stagecoaches and became the main route connecting Southern California to the desert and beyond.
1885: The California Southern Railroad completed its line through Cajon Pass, connecting San Bernardino to Barstow. Trains started hauling people, cattle, and freight through the mountains, transforming travel in the region.
1916: The first paved highway over Cajon Pass was finished, opening the route to automobiles and marking the beginning of modern highway travel in the High Desert.
1926: Route 66 officially included the road through Cajon Pass. This brought a wave of tourism, roadside businesses, and car culture to the area.
1969: Interstate 15 was built through the pass, replacing the old highway and making travel faster and more reliable — though not immune to traffic jams and winter weather.
1989: A tragic train accident occurred when a Southern Pacific freight train lost its brakes and derailed in the pass. The crash caused a deadly pipeline explosion and became one of the worst accidents in the region’s history.
2016: The Blue Cut Fire tore through Cajon Pass, forcing evacuations and destroying homes. It spread quickly due to high winds and dry brush, reminding everyone just how dangerous fire season can be.
Present Day: Cajon Pass remains one of the busiest mountain crossings in Southern California. Whether it’s semis on the freeway, Amtrak trains, or long freight hauls, the pass is still doing what it’s done for centuries — carrying people and goods across the mountains.