Union Pacific’s historic Big Boy steam locomotive No. 4014 is touring the Union Pacific system throughout 2019 to commemorate the transcontinental railroad’s 150th anniversary. The Big Boy’s return to the rails is the product of more than two years of meticulous restoration work by the Union Pacific Steam Team. No. 4014 is the world’s only operating Big Boy locomotive. The ‘Big Boy’ will arrive in Mason City at approximately 2:00pm for an overnight stop. Due to the dynamic nature of these operations, running times and scheduled stops are subject to change. The most accurate steam schedule information always will be located on this page > https://www.up.com/heritage/steam/schedule/index.htm