Union Pacific Challenger No. 3985 is the largest and most powerful steam engine in the world and the last locomotive of its class still operating. Here, you'll meet the people who keep this giant running, hear about the rise and fall of steam power, and step inside the vintage roundhouse in Cheyenne, Wyoming, where crew members share their thoughts on being part of a fading era as they restore the last steam engine built for Union Pacific, 4-8-4 No. 844. Color, stereo, 46 minutes. #0RV9250