no TopFlix. Esteemed for its scenic beauty and respected for the difficulty of its terrain, Tennessee Pass has been a magnet, drawing railfans and photographers to Colorado's mountains for years. When word spread that Union Pacific was closing the pass in 1997, interest climbed to an all-time high. Along with visitors from throughout the world, Pentrex traveled to this revered line to document its final months of operation. Our efforts were rewarded with a high volume of movements and an outstanding mix of trains. The grit of heavy-haul railroading is an awesome sight. Coal trains slug it out on the 3 percent grade leading to the 10,000-foot summit. Colorado's highest snow-capped mountains loom over toiling freights. Squealing flanges echo off canyon walls as trains grind through serpentine curves, and past the raging waters of the Arkansas River.