Burlington Zephyr, April 1934 Pioneer Zephyr Pioneer Zephyr (rear View) Pioneer Zephyr The Burlington Zephyr (a.k.a. the Pioneer Zephyr) The Pioneer Zephyr was a diesel-powered train . On May 26, 1934, it set a speed record when it made 1,015 miles non-stop in 13 hours 5 minutes between Denver, Colorado ,