Union Pacific's last numbered GP20 in a series of 30 units idles away the night at Provo Yard on Feb. 5, 1977. The 2000 horsepower EMD was built new for the UP in August 1960. In just over a year from the date of the photo, it was retired from the active roster and sold to Precision National Corp. of Mount Vernon, Illinois who rebuilt it into a GP21 and sold it to Agrico.