The silence of a chilly winter's morning is quickly interrupted by the unmistakable General Electric "chug" as four of BNSF's finest spit hot diesel exhaust into the air and echo their sound off the snow covered woods fighting gravity to keep Z WSPSBD9 04L and its 4600 feet of priority trailer traffic moving a track speed up the steep and slippery grade of Edelstein Hill. These Willow Springs, IL to San Bernardino, CA "Z" trains are unique in the sense that they almost always run with a solid consist of semi trailers and no doublestacks; a once common practice in the bygone era of the Santa Fe, now a rare sight on the rails today. Edelstein is the highest point on the railroad's Chillicothe Subdivision sitting at 814 feet above sea level and, once crested, marks the end of a 6-mile, 1.1% climb out of the Illinois River Valley for westbound trains.