Prior to purchasing the entire production fleet of six units, the Utah Railway Company tested three of MPI's MK5000Cs in coal service on Soldier Summit. They only operated for about three months in demonstrator/SP paint prior to receiving a full gray/red repaint at MPI in Boise. Here's the second of only two photos I shot of the demonstrator trio headed west with 67 loads of coal approaching the Thistle Tunnels in Spanish Fork Canyon.