Southern Pacific No. 2521 is a class C-9 2-8-0 steam locomotive it was built by the Baldwin locomotive works, and was outshopped in August 1907, and started work on the SP the following year.
It was in service until it was retired in 1957, and spending most of it working life in northern California and Oregon, then in Yuma for its last few working years, having travelled an estimated 2.5 million miles.
She is now placed on static display in the city of Yuma Arizona.