The Rock Island was one of several railroads competing in the Chicago–Denver passenger market. The
Chicago, Burlington and Quincy Railroad started the streamliner era in the United States in 1934 when its
Pioneer Zephyr made its special "Dawn-to-Dusk" run from Denver to Chicago in 13 hours 5 minutes. By 1936 both the Burlington's
Denver Zephyr and the
Union Pacific Railroad's
City of Denver were locked in head-to-head competition, each with new equipment and a 16-hour schedule. The Rock Island's offering was the
Rocky Mountain Limited, operating traditional heavyweight cars on a 27-hour schedule. Although mired in bankruptcy, the Rock Island introduced six new streamlined trainsets, known as "
Rockets", in 1936. Pleased with the results, the Rock Island bought two new sets of streamlined equipment for Chicago–Denver train. The new train, christened, the
Rocky Mountain Rocket, entered service on November 12, 1939. In contrast to the
Rocky Mountain Limited, the
Rocket required only twenty hours. A section split off at
Limon, Colorado to serve
Colorado Springs. At the time the
Rocket was the only train that offered a one-seat ride between Chicago and Colorado Springs. The new train was profitable, despite the slower running time compared to the Burlington and UP streamliners. Further competition arrived in 1942, when the
Missouri Pacific Railroad and
Denver and Rio Grande Western Railroad introduced the
Colorado Eagle between
St. Louis, Missouri, and Denver. Facing steep competition from airlines and improved highways, the
Rocky Mountain Rocket lost its sleeping and dining cars in July 1965. Snack cars were added to replace the diners and remained in service until the train was discontinued 15 months later. The last train ran on October 16, 1966. Among its final passengers was the railfan and photographer
Otto Perry. Unnamed train numbers 7 and 8 continued to operate between Chicago and Omaha, but the name was gone, along with all Rock Island passenger service west of Omaha. After a year without a name, it was renamed
The Cornhusker. In 1970, the train was renamed the
Quad Cities Rocket after its western terminus was cut all the way back to
Rock Island, Illinois. The train continued in this truncated form alongside the once-proud Rock Island's other remaining passenger train, the
Peoria Rocket, after the formation of Amtrak. From 1971 onward, Illinois provided subsidies for the train. By this time, it was down to just two coaches. What remained of the train made its last run on December 31, 1978. == Route ==