The Arizona and Colorado Railroad ran from Cochise to Kelton, AZ, where it branched off to the west and went across the mountain above Gleeson, AZ, and served the Copper Belle and El Tejon mines, among others. In 1910 it became part of the Arizona Eastern system, itself a subsidiary of the Southern Pacific Railroad.
After the 1924 consolidation by the Southern Pacific it was simply called the Gleeson Branch.