GREELEY, Colo. — Colorado has two opportunities to catch the world's largest operating steam locomotive over the next week as part of its limited fall travel schedule.
Union Pacific Railroad's Big Boy No. 4014 returns to the state this fall after a trip earlier this year in July. The train measures approximately 132 feet long and weighs 1.2 million pounds.
The behemoth locomotive is one of 25 that were built for Union Pacific during World War II. Eight were maintained, but Big Boy No. 4014 is the only one still operational.
You can see it for yourself on Tuesday, September 30, when Big Boy No. 4014 will depart Cheyenne, Wyoming at approximately 11 a.m. and make it to Greeley, Colorado around 12:45 p.m.
Then around 12:30 p.m. on Wednesday, October 1, it will travel from Eaton, Colorado back to Cheyenne. The locomotive will turn in Speer, Wyoming, returning to Cheyenne around 5 p.m.
Anyone who wants to see the gargantuan train in person, take pictures or video, is asked to stand 25 feet back from the railroad, Union Pacific advised. While it's tempting to get a closer look, the railroad said fans should never take a photo or video on the train tracks or climb on the equipment.
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Photos: Big Boy No. 4014's July 2025 Colorado stop
After this trip between Wyoming and Colorado, train enthusiasts can look forward to 2026 when Big Boy No. 4014 is expected to make a "monumental journey" to celebrate America's 250th birthday, Union Pacific said.
A map showing Big Boy's route and locations where you can catch a glimpse will be available on Union Pacific's website, found here.
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