This rail line was constructed to serve the silver mines in Lake Valley, NM. One mine deposit named the "Bridal Chamber" produced over 2 million ounces of silver, one of the richest pockets ever discovered. The town was in decline in the 1890s when the US government decided to demonetize silver. That action prompted the closure of many mines and the resulting ghost towns in many places across the western United States.
Thanks to Dr. James H. Olsen, Jr., PE for contributing information about this route.