Sky9 captured this video of Union Pacific's Big Boy locomotive in a rail yard in north Denver Wednesday. Wednesday morning, Union Pacific's Big Boy No. 4014 departed from Denver Union Station back to the locomotive's home base in Cheyenne, ending the locomotive's "Heartland of America Tour." There was no public access to see the departure from Denver, but the legendary locomotive made whistle stops in Greeley and Strasburg at the conclusion of its fall tour.