The Zephyr Rocket was an overnight passenger train operated jointly by the Chicago, Burlington and Quincy Railroad ("Burlington Route") and the Chicago, Rock Island and Pacific Railroad ("Rock Island Lines") between Saint Louis, Missouri and the Twin Cities of Saint Paul and Minneapolis, Minnesota, with major intermediate stops in Burlington, Cedar Rapids, and Waterloo, Iowa.

Motive power and equipment were pooled and traveled the entire distance without change.

[1] They also carried round-end observation cars with the train's name emblazoned on the rear for several years.

In 1964 the train was still earning money above its direct costs, at least for the Chicago, Burlington & Quincy.

[2]: 113 Reinstatement of direct passenger rail service between the Twin Cities and St. Louis is infeasible on the original route, as a key part of it, between Burlington and Cedar Rapids, was abandoned when the Rock Island ceased operations in 1980.