Union Pacific's Big Boy locomotive #4014 (4-8-8-4) runs past a crowd of amazed onlookers at Nunn, Colorado.

UP Big Boy 4014 runs through the cut at Speer, Wyoming as it begins the journey towards Denver, Colorado where it was displayed for a day at Denver's Union Station.

Ed Dickens, Union Pacific Engineer and Senior Manager of Heritage Operations for Union Pacific Railroad, works in his office on UP Big Boy 4014 as it runs through the clouds in Cheyenne, Wyoming. ... (more)

The UP 4014 backs into Denver Union Station. Steve Lundt photo

The UP 4014 leads the 2022 Museum Special over Sand Creek just moments before ducking under the I-270 overpass in Commerce City, Colorado.

Masters of their craft. The California Zephyr made a stop in Denver, Colorado right after the Union Pacific's Big Boy locomotive backed into Union Station. Gary Meyer on left is the engineer of ... (more)

There was a rare sight in downtown Denver this weekend as Union Pacific Big Boy 4014 (4-8-8-4) backed a special passenger train into Union Station in downtown Denver, Colorado

Engineer Ed Dickens moves the Big Boy in the Union Pacific Yard in Cheyenne, Wyoming.

Union Pacific's Big Boy has just spun around on the wye and is headed towards the Moffatt Subdivision to spend the night with Denver's skyline standing tall behind them.

Union Pacific's Big Boy beats across the diamond and Sand Creek in Commerce City as they approach Denver.

Union Pacific's monstrous Big Boy 4014 slides south onto the Greeley Subdivision en route to Denver for its only scheduled service weekend for 2022.

Going UP the hill....not as much fun as heading down....still, the Big Boy is making its way to Cheyenne on a snowy November morning.

UP 4014 (4-8-8-4) runs east of Cheyenne, Wyoming and muscles through Archer Hill. It was just announced that instead of the longer run to California this year, the Big Boy will make a run to Denv... (more)

UP 4014 rests on the siding at College Station, in preparation for the next day's excursion.

Big Boy #4014 makes the final push towards Ogden for the Spike 150 celebrations in May 2019. Despite the snow squall, the Big Boy put on a memorable show!