Nickname for any of the 'GP' series of diesel-electric locomotives produced by General Motors' Electro-Motive Division, or EMD. The letters GP stood for General Purpose, and denoted the intended use of these locomotives; they had good bi-directional visibility like a switcher, but the power of a road locomotive. The Geep was the first road-switcher design, which would soon replace the cab unit style hitherto popular on American railroads. Almost every locomotive in use in North America today is a road switcher, also known as a hood unit.

The first Geep was the EMD GP7 model, first built in 1949 for the Chicago & North Western Railroad. Over 2700 GP7 models were produced.

GP models produced:

1949-1954: EMD GP7
1500hp 16-567B engine. More than 2700 produced.
1954-1959: EMD GP9
1750hp 16-567C engine. More than 4000 produced.
19??-19??: EMD GP30
1963-19??: EMD GP35
2500hp 16-567 engine. Almost 1300 produced.
19??-19??: EMD GP40
19??-19??: EMD GP50
19??-19??: EMD GP60
(to be continued)