These postcards depict the early days of Durango, Colorado. According to The City of Durango, the town was created by the Denver and Rio Grande Railroad Company in September 1880 as a location for smelters to work the silver and gold being mined nearby. Durango’s more moderate climate at an elevation of 6,512 feet above sea level, a steady water supply from the Animas River, and the availability of coal made it a good choice. The city was named after Durango, Mexico, supposedly because the territorial governor at the time thought the geography was similar. (source)