Minnesota Transportation Museum's ex-Great Northern SDP40 is at the head of "The Last Mail Train," one of the features at Union Depot's Train Day 2017. The former NP RPO was used to deliver mail between St. Paul and Osceola, Wisc., that evening.
The EMD SD (special duty) series are a strong and reliable kind of locomotive which still serve America's rails today. They have proved themselves reliable by clocking in several million miles of freight service over several decades.