October 9, 2019, was an historic day as Union Pacific 4-8-8-4 4014 became the first “Big Boy” steam locomotive to operative under steam over southern California’s Cajon Pass! The big engine (recently restored to operating condition, and the largest steam locomotive in the world) is seen rounding the curve at Cajon Pass’ Summit as it makes its way west to the UP’s West Colton Yard in Bloomington, California. In a few days this engine will haul passengers over Cajon on a pair of fan trips from West Colton to Barstow and return (the next day). The massive machines were built by Alco in the early 1940s to carry heavy trains over the Wasatch Mountains between Utah and Wyoming.
