Challenger with elephant ears Union Pacific 4-6-6-4 Challenger No. 3985 loads returning passengers on the annual Cheyenne Frontier Days train at Cheyenne, Wyoming, on the afternoon of July 19, 2003. During the layover while patrons were attending the famous rodeo, the steam crew installed “elephant ears” smoke lifters to 3985, as the next day, the locomotive will be disguised as No. 3967 and pull a Rocky Mountain Railroad Club 50th anniversary special.