At the turn of the twentieth century, Phelps-Dodge Mining Company’s predecessor, the Detroit Copper Company, needed a more efficient form of transportation for its mines at Morenci. A railroad was the obvious answer, but the landscape it would traverse would be challenging. The Detroit Copper Company chose to construct a narrow gauge railroad from its mines at Morenci to the town of Guthrie, where it would connect with an existing railroad. A narrow gauge railroad was better suited for overcoming the topographic obstacles. Three tunnels and five 360 degree loops were necessary to complete the line into Morenci. The little 18 mile line, known as the Morenci Southern Railway, served the area from 1900 until 1922, when it was dismantled.