Activity at Harmony Borax Works in Death Valley ceased with the development of the richer Colemanite borax deposits at Borate in the Calico Mountains, which were discovered in 1882 and began operations in 1890, where they continued until 1907. Initial hauling to the Atlantic & Pacific Railroad was done again by the 20 mule teams, but were retired as soon as Smith completed the long Borate and Daggett Railroad.