The Detroit Copper Mining Company operated near Clifton and Morenci, AZ, started in 1875 by William Church. Phelps Dodge purchased an interest in the company in 1881 and bought Church out in 1897. After a 1917 reorganization, the operation was known as Phelps Dodge Corporation, Morenci Branch.
Collection includes financial journals, payrolls, time books, and ore and freight records related to mining company operations. Includes financial records of Hotel Morenci (1904-1913) and Frisco Ranch (1909-1913).