Galloping Goose is the popular name given to a series of seven railcars (officially designated as "motors" by the railroad), built in the 1930s by the Rio Grande Southern Railroad (RGS) and operated until the end of service on the line in the early 1950s.

Originally running steam locomotives on narrow gauge railways, the perpetually struggling RGS developed the first of the "geese" as a way to stave off bankruptcy and keep its contract to run mail to towns in the Rocky Mountains in Colorado.

There was not enough passenger or cargo income to justify continuing the expensive steam train service at then-current levels, but it was believed that a downsized railway would return to profitability. The steam trains would transport heavy cargo and peak passenger loads, but motors would handle lighter loads.

Motors were not only less expensive to operate, but were also significantly lighter, thus reducing impact on the rails and roadbeds. This cost saving meant that the first Goose was paid off and making a profit within three weeks of going into service. RGS built more Geese, and operated them until the company abandoned their right-of-way in 1952.