Twelve miles east of Bakersfield, California, is Sandcut. While the mainline has been steadily climbing for most of those 12 miles, Sandcut has the first curve and is generally considered the beginning of the climb over the Tehachapi Mountains. Constructed by Southern Pacific, the line is now owned by Union Pacific. However, most trains crossing the Tehachapis are BNSF Railway trains (formerly Santa Fe), as typified by train Z-FRSCHI1-12A (Priority UPS - LTL Intermodal; Fresno CA to Chicago IL) with ES44C4 6606 on the head end. Ahead lies the famed Tehachapi Loop, in which the tracks loop over themselves in order to gain elevation.