The Denver and Rio Grande Railroad opened vast new markets to sheep and cattle ranchers, and Cimarron became one of the busiest loading stops in Colorado. Breeding stock wintered in valleys to the west, and trains or spring drives brought cattle and sheep to the high country near here for the summer. In the fall, ranchers drove their herds down out of the mountains to waiting trains in a day-and-night rush to keep animals watered and fed amid raucous noise, repulsive smells, and choking dust. Twenty-car-long trains moved up to 45,000 sheep and cattle each season from these mountains to packing plants and tables around the country.