The Denver Zephyr was a streamlined passenger train operated by the
Chicago, Burlington and Quincy Railroad between Chicago and Denver.
It operated from 1936 to 1973. The Denver Zephyr continued operating
after the Burlington Northern Railroad merger in 1970. BN conveyed the
train to Amtrak in 1971; Amtrak would merge it with the
Chicago–Oakland San Francisco Zephyr and drop the name in 1973.