Union Pacific Big Boy Tour 2024. 4014, the world’s largest steam locomotive, will return to the rails this summer with a scenic tour across mountain ranges and. Big boy 4014 will travel from wyoming to california in the.

The ‘heartland of america tour’ will be big boy’s second tour of 2024. 4014, the world’s largest steam locomotive, will return to the rails this summer with a scenic tour across mountain ranges and high desert.