On a pristine winter's afternoon, a BNSF Provo-Denver freight curves through Spanish Fork Canyon at milepost 673, just west of Narrows, Utah. Milepost 673 is the distance measured east to Denver, Colorado via Tennessee Pass and Pueblo (the original D&RGW mainline). This train actually has about 500 miles to go, via the Dotsero Cutoff and the Moffat Tunnel, to reach the BNSF yard in Denver.