The City of Walsenburg traces its history back about 150 years. The settlement was first established as La Plaza de los Leones which was named after the Leon family on the north side of the Cuchara River by Don Miguel Antonio Leon and a family named Atencio. In 1870, Fred Walsen settled nearby and opened up his large mercantile, making the town an attractive location for German settlers. After Fred assisted in the incorporation of the town's 320-acre (1.3 km2) site, it was suggested that he be honored by formally naming the new town "Walsenburg". In 1876, Walsen also opened the area's first coal mine, and the development of the town was influenced for a century by coal mining in the region. An estimated 500 million tons of coal was mined until a combination of corporate mergers, environmental regulations, and enforcement of mine safety regulations led to the closure of virtually all mining in the area.