sentences:  The "Rocky Mountain Rocket" ran from 1939 to 1966; the train was discontinued prior to the creation of Amtrak in 1971.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.