One of the locomotives, The Challenger Union Pacific 3985, was built in 1943 and is the little sister to "The Big Boy." ... Union Pacific 5511 was built in 1923 and hasn't run since 1956.

The Challenger Union Pacific 3985, Centennial Union Pacific 6936 and Union Pacific 5511 are the locomotives that are being donated to RRHMA.

Union Pacific 5511 was also donated to RRHMA. Since then, the nonprofit has been hard at work restoring the 1943 locomotive to its former glory. Shop foreman Alex Beams said it last ran in 2010.