Built in 1968 as a Canadian National SD40, this locomotive is now 57 years old, with a life that saw it upgraded to an SD40-2 for BN/BNSF. Now it moves various traffic for WAMCO road Swan Ranch Railroad in the much newer rail park that has sprawled southwest of Cheyenne, WY. Of the 4 Swan Ranch locos I saw on site, the helper here is WAMX 4184, which began its life as a Mopac SD40-2.