The Worlds Largest Operating Steam Engine! Union Pacific Big Boy No. 4014 Fall 2025 Denver Excursion

Union Pacific Big Boy No. 4014 — Cheyenne to Denver, 2025
Union Pacific’s legendary Big Boy No. 4014 storms south from Cheyenne, WY to Denver, CO on its second Denver run of the year, teamed up with SD70M No. 4404 and a 9 car excursion consist.

For this trip, the UP Steam Crew gave 4014 a rare experimental look, elephant-ear smoke deflectors, recreating a 1940s test once done on sister engine No. 4019. This marks only the second time ever an operating Big Boy has worn smoke deflectors in service.

From the wide-open plains of Wyoming to the industrial heart of Denver, watch 4014 thunder across the Northern Colorado — rolling through Greeley, Pierce, and Platteville before arriving at North Yard in Denver via the old Belt Line.

The next morning, the chase continues as 4014 pulls out of UP’s Denver North Yard, backs down the Belt Line, and departs north from 36th Street Yard — charging through Fort Lupton to close out another unforgettable run.

Chase Timeline:
0:00 – Cheyenne, WY
1:08 – Carr, CO
2:08 – E Main Ave Grade Crossing , Pierce, CO
2:49 – Tenth St Crossing Next To Colorado Model Railroad Museum, Greeley, CO
3:24 – 18th St Crossing, Highball Greeley
3:50 – County Road 36 Crossing, Platteville, CO
4:27 – Double Stop At Fairfax Park , Guest Drop-off
8:52 – York Street grade crossings, Denver, wye-Ing the train @ 36th St Yard
14:34 – Belt Line To North Yard, Washington St Crossing
15:56 – Backing In To North Yard
18:14 – Morning Departure from North Yard
20:07 – Backing Down onto the Greeley Sub
21:43 – Departing Denver's UP 36th St Yard
22:52 – Commerce City, CO E 64th Ave Crossing
23:53 – Final Shot----- Fort Lupton, CO Ninth St Crossing