Caption: In early 1959, you could still find steam power handling mainline trains on CN in southern Ontario--but not for long. According to Don McQueen's Canadian National Steam!, midnight May 31, 1959 was "the effective dieselization of Central Region. All steam stored for emergency use." So, savour this view of GP9 4523 assisting Northern (4-8-4) 6112 through the "Cowpath" and up the Copetown hill...it is a show that will only continue for a few more months.