Big Boy,” a 1.2 million-pound locomotive, is back in Colorado after being restored to the world’s largest operating steam ...

The world's largest operating steam train is in Denver. Union Pacific's legendary Big Boy No. 4014 locomotive made a pit stop ...

DENVER (KDVR) — The world’s largest operating steam locomotive, known as Big Boy No. 4014, is coming back to Colorado — and this time, it’s bringing a friend. Union Pacific, a railroad ...