Big Boy 4004 parties like it’s 1941 again! Join us at Cheyenne’s Holliday Park to talk to the restoration crew responsible for bringing Big Boy 4-8-8-4 No. 4004 back to its 1941 appearance in 2018. The giant locomotive has been on display for almost 60 years and is once more looking like its original appearance. It’s the only Big Boy on display in its home territory and it's located in a historic railroad city that is all about big power for steep grades and high volumes of freight.