Built in 1907 in Philadelphia this locomotive pulled passenger and freight trains an estimated 2.5 million miles.
# 2521 was donated to the City of Yuma by Southern Pacific in 1957.

As a sidenote: Southern Pacific laid tracks up to the California side of the Colorado and then defying authories, laid the track across the bridge at the Yuma Crossing in the dead of night allowing the first train to enter Arizona through Yuma on September 30, 1877.