Union Pacific’s No. 014 “Big Boy” makes its way through Navasota, Friday, Oct. 4, 2024. Big Boy, making its third trip to the Houston area since its restoration in 2019, ...

The last existing Big Boy in operation, and perhaps the most famous, is the Union Pacific Big Boy No. 4014. You can take a ride on the Union Pacific Big Boy No. 4014. Brandon Bell/Getty.

People line the railroad tracks in Crete as Union Pacific’s Big Boy Number 4014 steam engine rolls through as part of its Heartland of America Tour on Sept. 9, 2024.

In total, 25 “Big Boy” locomotives were built with the first being delivered to Union Pacific in 1941. Big Boy No. 4014, the locomotive coming to Texas on tour, was delivered in December 1941.

Union Pacific built 25 Big Boy locomotives in the 1940s to conquer mountains. No. 4014 is the world’s only functioning Big Boy. To stream 9NEWS on your phone, you need the 9NEWS app.

Union Pacific’s Big Boy takes its place near Union Station in Ogden on Friday, July 19, 2024, ready for the weekend’s display. Rail fans wait to catch their first glimpse of the Big Boy at ...