Portrait of a classic: C&S 629’s engineer is leaning way out, looking back to the brakeman’s signals as he backs a cut of livestock cars across the South Platte River and into the labyrinth of sidings serving the Denver stock yards. Business is brisk: The annual National Western Stock Show & Rodeo opens in just a few days, drawing stockmen, cowboys and visitors from throughout the west to the nearby coliseum and arena.