Big Boy Arrives in Sparks 🚂 The Union Pacific’s legendary Big Boy No.4014 is made a whistle-stop in Sparks! Many came out and see the world’s largest operating steam locomotive on Sunday, July 14, from 5 to 8 p.m. across from the Nugget Casino Resort on Nugget Avenue. For the safety of those viewing the Big Boy, the I-80 East Nugget Ave. offramp and sections of Nugget Ave. was closed from 4 to 9 p.m. 🎥 @renonevadaimages #sparks #bigboy #locomotive #nevada