The 1932 Plymouth 0-6-0 switch engine was one of the first internal combustion engines used by the Missouri Pacific Rail Road, ushering in a new form of motive power that eventually replaced the steam engine. The locomotive is mechanically driven through a transmission and has drive chains to the wheels. It was last used at the Mackie-Clemens Mine #22 in the 1970s and was restored by the Heartland's in 1999.