Electro-Motive's GP20 was essentially the builder’s first entry into what is now considered second-generation diesels. To some extent the locomotive was an experimental design offering a turbocharged version of EMD's reliable model 567 prime mover. It was also the first road switcher the company offered with a standard low nose/hood that tapered away from the cab (the builder would refine this design in the later GP30 model). When production ended on the GP20 a little more than a half-dozen domestic railroads purchased more than 200 examples of the locomotive. Today, this resilient little road switcher can still be found in operation on numerous short lines are the country. Additionally, at least two are known to be officially preserved; Southern Pacific #7207 used by the Blue Ridge Scenic Railway and Western Pacific #2001 at the Western Pacific Railroad Museum.